Derral Cheatwood. 21st Century Criminology: A Reference Handbook. Editor: J Mitchell Miller. 2009. Sage Publication.
Although questions about weather and crime, climate and crime, and season and crime are each different, they share a common assumption: that weather somehow influences criminal behavior. Many of the oldest beliefs about an association between weather and human behavior were based on otherworldly causes, ranging from weather gods to the positions of heavenly bodies. Astrology, which dates back 5,000 years, is a classic example of that approach. Other explanations, from Hippocrates some 2,400 years ago to Montesquieu in 1748, have assumed that the climate of specific areas influenced the populations living in those areas—for example, that hot southern climates produced hot-blooded people and cold northern climates produced cold-blooded people. Beginning in the 1800s, criminologists from Adolphe Quetelet to Cesare Lombroso argued that climate influenced the biology of the individual, which could lead the population of a given climate toward higher rates of crime. Most of those assumptions—in fact, pretty well all of them—have been discounted by recent scientific research. However, a number of modern theories of crime provide some well-reasoned arguments as to why weather and, by extension, climate and season, should quite logically be expected to influence criminal behavior.
This chapter defines what is generally meant by weather, season, and climate. It considers some of the theories that would lead one to expect a relationship between weather and crime and concludes that the routine activities theory of crime and theories that focus on stress in social interactions offer the best explanations for the relationships seen. It then looks at the data that suggest that weather, climate, or season have an effect on crime. Finally, taking all this into consideration, it reaches some conclusions as to whether weather, climate, or season influence crime rates or crime patterns and if so, how.
Weather, Climate, and Season
There are actually three aspects of weather that have been studied in criminology: (1) weather itself, (2) season, and (3) climate. Weather, as defined in the Glossary of Meteorology(Glickman, 2000), is the state of the atmosphere of the earth, and the major components of that atmosphere that criminologists examine (and on which the local meteorologist reports) are temperature, humidity, precipitation, cloudiness, wind, and barometric pressure. The Glossary notes that weather commonly refers to short-term atmospheric conditions, usually thought of in terms of hours or days. Many of the modern studies of the impact of weather on crime use day-to-day changes in these weather elements as independent variables.
All natural events, including weather, occur in the dimensions of space and time. Climate is a pattern of weather characteristic of some given space, usually a large geographic area. Obviously, the weather will vary day to day and month to month both in southern Texas and in northern Minnesota. However, just as obviously, the weather in southern Texas will characteristically be hotter and drier, and the weather in northern Minnesota will be colder and wetter. A pattern of weather characteristic of a period of time, usually months, that recurs with regularity from year to year constitutes a season. No matter what one day’s weather may be, or what the climate may be, in almost all locations the weather changes during the year, being hotter during one period and cooler during another. The fact that the changing seasons affect human behavior patterns is confirmed by data on almost all human activity, including crime.
Because climate and season describe different aspects of weather, it is important to consider each of them separately when discussing the impact of weather on crime. Crime is a social behavior, and virtually every behavior in which humans engage is affected in minor or major ways by the weather that surrounds us, the change of seasons that change that weather, and the common weather patterns that define our climate. Both logic and a superficial review of crime data support the appearance of some relationship of weather to crime, and criminologists address questions about what the nature of that relationship is and how we can explain how weather either directly or indirectly brings about that relationship.
Theoretical Models of the Relationship of Weather and Crime
Early philosophers believed that the weather had an effect on the biological and psychological makeup of individuals, and thus of cultures, with temperate climates making for temperate personalities and hotter climates making for more aggressive personalities. Characteristically, they argued that hotter days, hot seasons, and hot climates influenced individuals directly, making them less capable of controlling their inhibitions and more subject to impulsive and often aggressive behavior. Society, then, merely reflected those individual influences.
During the birth of modern social science in the 1800s, a Belgian statistician named Adolphe Quetelet formulated the thermic law of delinquency, which held that crimes against person are more common in hotter climates and seasons, whereas crimes against property are more common in cooler climates and seasons. During the rest of that century and into the 20th century, many of the first criminologists, from Cesare Lombroso and Enrico Ferri to Gustav Aschaffenburg, supported this thermic law. In the United States, some researchers blamed excessive heat for stimulating the emotions, increasing irritability, and bringing about lower levels of social inhibition, with a resultant inability to control one’s impulses. All of these factors, they argued, led to the higher murder rates seen in the hotter southern areas of the United States. This was carried further to a racist climatic determinism that argued that blacks, tracing their ancestry to the hot regions of Africa, carried a hereditary tendency to aggression and lower impulse control derived from that climate, which resulted in the higher murder rates among African Americans.
Others, however, rejected this biological determinism and began to observe that the correlation of weather and crime was mediated by culture and the changing nature of social interactions (Falk, 1952, provided an excellent review of this literature). In his comprehensive examination of suicide as a social phenomenon, one of the outstanding early sociologists, Émile Durkheim (1897/1951), countered these explanations and the thermic law of delinquency. Examining data on crime as well as suicide, he was one of the first scholars to bring a systematic scientific method to bear on the relationship of weather to crime. He pointed out that the patterns of personal aggression, both murder and suicide, that appear characteristic of certain climates at one time in history are not necessarily characteristic of those same climates at other times in history. He also demonstrated that within any climate different subcultures in the population will display different levels of aggression. It is, he argued, not the climate but the culturally framed social activity of the people who live in that climate that fosters or prevents aggression.
In examining seasonality, Durkheim (1897/1951) used data on Europe from much of the 1800s that did in fact indicate higher murder rates and suicide rates in the summer. However, after an analysis of those data, he concluded that it is not heat per se that brings about changes in the individual that lead him or her to commit murder or suicide. He argued that instead, the rates for those instances of premature or voluntary death occur during the summer because during that season social life is far more active, and social interactions are more intense. In noting this he was among the first to understand that the influence of weather, including seasonal or climatic effects, was indirect, bringing about changes in social interactions, which then changed the levels of crime and suicide.
During the growth of modern criminology in the 20th century, theorists increasingly came to follow Durkheim’s lead and examined how weather, climate, or season affects our day-to-day social interactions. Throughout the century, a variety of explanations were tested using increasingly sophisticated methods, and by the beginning of the 21st century two models had evolved to explain weather’s impact on crime: (1) interactional theories focusing on stress and (2) routine activities theory.
Interactional theories look at the relationship of the individual to the social milieu in which he or she lives. In short, how do people manage to get along with each other day to day? In this model, stress—the need to constantly adapt to changing conditions and accommodate others in social interaction—is a constant in all human behavior. We react and respond to our environment using socially learned habits of adaptation provided by our culture. That environment consists not only of other people and our interactions with other people but also the physical world. These adaptations usually are quite functional and allow the individual to deal with normal levels of stress. In cases of extreme weather, however, these normal adaptations are stretched beyond their functional limits, and normal physical, psychological, and social reactions begin to break down.
The way we are taught to accommodate increased stress brought about by hot weather, and even the way we are allowed to accommodate, is culturally, socially, and economically conditioned. In very hot weather in public work settings in the United States, men may take their shirts off. Women, by law and by cultural convention, may not. In very hot weather, middleand higher-class people can stay inside their air-conditioned homes. The poor, unable to afford air conditioners and the energy to run them, cannot. In other words, the way groups of people are able to adapt to increased stress is based on everything from economic status to gender. During times of stress, these differences can result in increases in criminal behavior in some populations more so than others.
This stress is not all social or psychological. Heat has a very real physical impact on our bodies. During periods of increased heat we perspire, and blood flow is increased near the skin to better dissipate heat. However, at some point our bodies are physically unable to keep up with the stress produced by increasing heat (and accented by increasing humidity). Research has established that there are qualitative points, called discomfort points, at which heat (or the relationship of heat and humidity) begins to noticeably affect most people, and those points show up as having a relationship to some crimes, notably, assault and murder.
Beyond the biology of the individual, however, crimes are more often the result of stresses that derive from human interaction, and both weather and season change our patterns of behavior and thus, indirectly, the nature and level of stress to which we are subjected. These common patterns of behavior are called routine activities, and they are the focus of the second major approach to understanding the impact of weather and season on crime.
Routine activities theory, developed by Cohen and Felson (1979), is probably the most widely used model to explain the relationship of weather, climate, and season to crime. This theory holds that crime is the result of the convergence in time and in space of motivated offenders, suitable targets, and the absence of capable guardians. Note that it is not a causal theory that seeks to explain why individuals become motivated to commit crime; instead, it simply states that when people who might decide to commit a crime (or who are already intent on committing a crime) wind up at the same place and at the same time as people or places that are suitable targets, and there are no other people or structures or props present that can protect those suitable targets, crime will increase.
Weather, climate, and season can have an impact on all three of those components (i.e., motivated offenders, suitable targets, and lack of guardians). The time around Christmas, for example, often finds us economically stressed, with an immediate need for cash to buy presents (or to pay bills from credit cards used to buy those presents). Field studies of armed robbers have revealed that robbery is often the result of a perceived need for immediate cash and that the preferred targets are individuals who are likely to have cash or valuables and unlikely to have a defensive weapon. Those two factors predominate around Christmas. Furthermore, the mass of shoppers in malls and in parking lots can overwhelm security personnel and normal security measures, leaving the suitable targets without adequate guardianship. And sure enough, FBI data confirm that robbery is the only Crime Index crime that is regularly more common in the deep winter months (December and January; Falk, 1952).
Even a look at the same type of crime, but different sets of victims, reveals that the common activities in which people engage are significant influences on the crimes they commit. McCleary and Chew (2002) examined seasonal risks for homicide but focused on victims who were children under age 15. They confirmed that the summer season peak found for adult victims was also characteristic of school-aged children, but for children under age 5 they found a significant peak in homicide victimization during the winter months. Most offenders in these child murders were young mothers, and the event precipitating the homicide was likely to have involved demands for food, clothing, or attention. These demands were most likely made at home, were more stressful for young mothers with less experience, and were accented during winter months, all of which explain the higher murder rates for young children during that season.
In research that compared routine activities theory with a more traditional psychological theory suggesting a direct association of temperature and aggression, Hipp and colleagues (Hipp, Bauer, Curran, & Bollen, 2004) found that routine activities theory was more effective in explaining the differences found in both violent and property crime. As we will see, data on a variety of different crimes over a number of years and in a variety of places support that conclusion. It is also important to point out that we have to be very careful not to confuse levels of scale when comparing a sociological theory such as routine activities theory with a biological or psychological theory. Even when considering stress, we have to be careful to make sure our data and our theory are derived at the same level of scale. Durkheim (1897/1951) pointed out that one should explain social facts only with other social facts. If we have data on crime rates that are derived from large population groups, for example, we have to be sure our theories are not reducing our explanations for a group’s crime rate to the psychological makeup of the individuals of that group.
Most modern explanations of how weather affects crime, then, rely either on a model suggesting that weather increases the level of interactional stress and pushes our culturally provided adaptations to their breaking point or one that suggests that weather has a role in changing the routine activities and patterns of social interaction, which changes the likelihood of crime. These theories are based on crime and weather data, and they are continually being tested by researchers using ever more detailed and extensive data sets. This research has yielded findings that do seem to be consistent as criminologists examine the impact of weather and season on crime.
First, there is no question that very extreme weather conditions affect crime patterns, just as they affect all other human activities. If a hurricane strikes a city with 100-mph sustained winds, burglary will go down during the hours that those winds are present. This is not because there are no motivated burglars in the city, or because there are no unprotected homes or businesses with valuables in them (in fact, there are probably more unprotected homes, because individuals with resources may have evacuated the area). The simple fact is that when it is impossible to walk on a street, the burglars cannot get to the homes. However, in a study of the impact of Hurricane Hugo, James LeBeau found that, once the hurricane had passed, there was a significant increase in calls to police for burglary as well as to report a “man with a gun,” suggesting a possible increase in defensive gun use (LeBeau, 2002). When the motivated offender is able to move about, when suitable targets are available, and when the activities of guardians such as the police are directed elsewhere, crime increases.
In general, criminologists do not look at such extreme weather events. Instead, they conduct their research on the range of normal variations in weather factors, seasonality, or climate, and look for changes in crime patterns that relate to changes in those factors.
Although variations in climate and its effect on people served as explanations of differing crime rates in much of the early literature on weather and crime, the impact of climate on crime has been largely discounted. The earliest observations that led criminologists to suggest climatic impacts on crime were geographic differences in crime rates. In the United States, this was in particular the consistently higher murder rates found in the South. It is a fact that murder rates in the South have been higher than in any other region of the United States since data on crime have been collected. Examinations of the correlation of the South with homicide rates has became progressively sophisticated over the past hundred years, and a significant debate has developed in criminology as to whether the association of murder and “Southern-ness” is due to cultural differences (particularly among minority populations) or to structural differences along economic lines. What is significant, however, is that in the dozens of scientific articles published on this question since the 1960s, climate is no longer considered as a possible explanation.
Research conducted by DeFronzo (1984) near the end of the 20th century may have effectively laid the climate and crime argument to rest. After controlling for nonclimatic variables, climate had only weak and indirect associations with crime rates. DeFronzo found that economic conditions, urbanization, and population demographics remain the primary predictors of overall crime rate (again, with the debate continuing over exactly which of the three carries the primary explanatory power).
From this, the research shifted initially toward seasonal effects on crime. Then, as computers gave us the ability to do increasingly complex research on increasingly large databases, criminologists turned to the examination of more precise, short-term weather factors.
Quetelet’s thermic law of delinquency argued that heat and violent behavior were related, such that violent crimes should be higher in the summer months and property crimes higher in the winter. A casual examination of Uniform Crime Reports data indicates that there is a considerable seasonal effect for both violent and property crime in the United States. However, when one looks at the Uniform Crime Reports for 1990 through 2003, it is obvious that the months in which the property crimes of burglary and larceny are highest are not in the cooler seasons but in July, August, September, and June (Hipp et al., 2004). Thus, a simple examination of the data challenges the thermic law. Research in other locations has also found seasonal patterns for particular crimes, although some of these patterns are not the same as those found in the United States. In England and Wales, robbery and burglary both increase in the winter, whereas personal crimes peak during the summer; in Ghana, the personal crime of assault is also highest between June and September. Landau and Fridman (1993) examined the seasonality of robbery and homicide in Israel and found that robbery followed a strong seasonal pattern of higher rates in the winter but that homicide, although somewhat more common during certain months, displayed no seasonal pattern (August was high, but July was low; March was high, but April was low). In the Southern Hemisphere, where the seasons are reversed, the patterns also are reversed. Studies of sexual abuse in Chile indicated that the months in which the number of cases were highest were November, October, and December (late spring and early summer in Chile), with the lowest number of cases appearing in late autumn and winter during the months of May, June, and July (Tellez, Galleguillos, Aliaga, & Silva, 2006).
Indeed, in the United States, a temporal pattern in which certain months are significantly high and certain other months significantly low is apparent in almost all crimes. The problem is to determine whether the pattern variation is seasonal or monthly. This may sound like the same thing, but there is a difference, and it is a very important difference for theory, research, and policymakers. If one looks at American data over the past five decades, one can see that a number of crimes are highest in the warmer months of June, July, August, and September (Hipp et al., 2004). Larceny (theft), burglary, aggravated assault, and rape all have peaks in July and August, with the third highest month most commonly being either June or September. So, looking at American data we see a seasonal pattern for rape, assault, larceny and burglary, with all being higher during summer months. Because two of these are personal crimes and two are property crimes, they obviously do not support Quetelet’s thermic law of delinquency.
Robbery and murder, on the other hand, show significant monthly patterns, but the months involved do not appear in any one season. July and August are also among the three highest months for murder in the United States, but the third most common month for high murder rates is December. This indicates a significant monthly pattern for homicide, yet it is clearly not a seasonal pattern. Also, robbery, which is considered a personal crime by the Uniform Crime Reports, is consistently at its highest during the months of December, January, October, and August (Cohn & Rotton, 2000).
What these data lead us to suspect, and research confirms, is that in any country the seasonal or monthly patterns characteristic of any crime are determined in large part by cultural patterns. In one of the most pronounced cultural effects, Zimring and associates (Zimring, Ceretti, & Broli, 1996) discovered that crime of all types drops by half in Milan, Italy, during the month of August, the month in which a large proportion of the Italian population goes on holiday. They noted that the opportunities for crime (suitable targets and the absence of capable guardians) do not decrease; in fact, there should be more unguarded homes and fewer guardians in place. The only conclusion that seems to fit their data is that “social processes unknown in American cities reduce criminal activity in Milan almost in half during the vacation month of August … Crime takes a holiday in Milan during August apparently because criminals take a holiday” (Zimring et al., 1996, p. 277).
In sum, the relationship between the hotter months of summer and a peak in rape and assault seems to be almost universal. However, although there is no such universal seasonal pattern for property crimes, robbery, or murder, many locations do show a pronounced monthly pattern for those crimes. Oddly, it appears that the thermic law of higher personal crimes in the summer and higher property crimes in the winter may hold for other locations, including parts of Europe (Rotton & Cohn, 2002, p. 487), but not for the United States.
When we examine the data on season and specific crimes in more detail, the results strengthen the idea that the seasons act on crime by bringing about changes in routine activities and increases in interactional stress. Recall that July and August are the most common months for murder but that the third month in which murder is most likely to occur is December. Obviously, July, August, and December have drastically different weather patterns. However, these are the months in which we tend to take vacations as well as the ones during which we interact more frequently with friends and family. As many of us are aware, those people who can cause us the most stress—who can really push all our buttons—are the same people to whom we are closest. These months also see an increase in alcohol consumption. Alcohol releases inhibitions and can increase aggression, and it is a common drug of abuse among young males, who constitute the group with the highest murder rates (as both offenders and as victims). Increased interactions among people with strong emotional ties, which produce increased stress, and the increased use of alcohol by high-risk groups during the summer and over the holidays should be expected to increase the incidence of homicides, and that is what we see. It is not the weather characteristic of the season but the nature of social interactions that are influenced and changed by that weather.
This proposition is further supported when one compares seasonal patterns of murder and assault. Criminologists frequently make the argument that aggravated assault and homicide are “sibling” crimes; that is, they are the same behavior—an attack by one person with the intent to do serious bodily harm to another—and the only real distinction is whether the victim lives or dies as a result of the attack. If this is correct, then we would expect to see the same pattern of July, August, and December being the most common months for aggravated assault, just as we did for murder. However, that is not the case. The months with the highest reported cases of aggravated assault are July and August, but then June and September tie for third. Not only is December not one of the highest, but also it is consistently the month in which the lowest number of aggravated assaults are reported. On the one hand, that could mean that murder and aggravated assault are not the same behaviors at all, but it is also possible that assaults occurring around Christmastime are less likely to be reported because, as our theories suggest, they are more likely to occur between friends or members of an extended family. And that is exactly what happens when criminologists look at the reports made to police. The reporting of assault goes down near the holidays, often because fights between friends or family are hidden, but fights that result in a death cannot be hidden, and the number of murders increases. As Anderson noted as early as 1989, “It is probably the case that within families, assaults are relatively unlikely to be reported to the police. Obviously, withinfamily [or within-friend] homicides cannot be correspondingly underreported” (p. 84).
In sum, it is not the weather characteristic of the season that directly increases aggression in individuals; instead, it is the social behavior characteristic of the season for each culture that changes the probability that criminal behavior may result, and this seems to apply across cultures. Most of the findings on the subject of weather and crime are based on American data, but research conducted in other nations suggests that although seasonal and weather effects on crime appear to be universal, the form they take is shaped by unique cultural patterns.
Although the results of research testing the impact of the full range of weather variables vary from study to study, there is fairly solid evidence for a relationship between crime and temperature, with lesser support for such a relationship between crime and humidity, precipitation, or changes in barometric pressure. A few isolated studies have found some impact of cloudiness, precipitation, or barometric pressure on crime, but most research using those variables does not. Only temperature seems to produce relatively consistent findings over the years (Rotton & Cohn, 2002, provided a good review of this research). Furthermore, temperature has been examined in a number of different ways. Basic raw temperature, as well as the discomfort produced by the addition of humidity in the temperature humidity index(originally called the discomfort index), have been tested. The temperature recorded at periods of time as short as 3 hours has been examined, as has the effect of consistently high temperatures over a number of days. Regardless of how it is tested, in one study or another, an increase in temperature has been found to correlate with increases in assault, homicide, rape, robbery, burglary, larceny, and domestic violence.
Studies that have examined the combination of weather effects and time effects on crime patterns have found that they are related. In line with routine activities theory, street crimes are consistently higher during weekends, when people engage in more leisure activities, have more time on their hands, are more likely to use alcohol, and are more likely to leave their homes for other entertainment venues. As a result, weekends are more likely to reduce guardianship for crimes such as larceny and burglary and are more likely to place demographic groups with higher propensities for aggressive crime (young males) in entertainment situations involving alcohol and in contact with suitable targets for aggression (anything from other young males to young females), with a concomitant increase in murder, aggravated assault, rape, and robbery. Temperature not only has a general impact on crime, but it also appears to compound or accentuate the impact that day of the week has on crime. Crime consistently increases on weekends, but research shows that it increases more on hotter weekends than on cooler weekends. Taking this even further, LeBeau and Langworthy (1986) made the insightful observation that the increase in both crime and police calls for service during the summer months should thus not be considered unusual, “since vacations from work and school are primarily extended weekends” (p. 139).
So, routine activity models are strongly supported by both seasonal and weather data, but what about stress? Researchers looking at assaults in Dallas during the early 1980s divided neighborhoods into low status, medium status, and high status and found that the link between the discomfort produced by a combination of heat and humidity during the summer and an increase in aggravated assaults during that time was significantly more pronounced in low-status neighborhoods. This fits neatly with the argument that it is the ability to cope with increased stress and discomfort over time that provides a key to understanding the relationship between weather and assaultive crime. Increases in assault were associated with increases in the temperature humidity index across Dallas. All three classes of neighborhoods showed calendar variations, with some increase during summer months and a peak in assaults during the weekend, but the increase was significantly more pronounced in neighborhoods where economic disadvantage limited residents’ options to accommodate increased discomfort. In those low-status neighborhoods, during periods of increased heat, assault increased at a higher rate than in the more affluent neighborhoods because the poor “are less able to control the comfort of their home and work spaces and are perhaps more susceptible to the complex manifestations of heat stress” (Harries, Stadler, & Zdorkowski, 1984, p. 598).
In sum, most factors of weather—rain, snow, fog, weather fronts, barometric pressure, or wind—do not display consistent results when tested for their impact on crimes. Only temperature seems to be related, and the relationship is both robust and consistent across most studies of weather and crime or season and crime. Higher temperatures, or higher temperatures combined with higher humidity, produce such discomfort that our adaptations to stress are stretched to their limits. This discomfort also changes our patterns of routine activities in ways that place us at higher risk of both property and personal crimes. At the societal level, the impact of weather is further mediated by day of the week, the demographic structure and cultural matrix of the population, and the socioeconomic structure of the population. As with so many other things, our cultural, economic, and physical environments modify how we are affected, and how we respond to, everything we encounter.
Complex research on weather factors and crime across long periods of time or in numerous locales requires the handling of extremely large data sets, and this has been possible only with the development of sophisticated datagathering meteorological instruments; the advent of the computer; and the development of analytical techniques to handle large, complex data sets. As a consequence, and despite significant early studies conducted with the limited data and analytical techniques available, the study of detailed weather patterns and resultant crime changes is only a little over three decades old. In that short history there are some contradictory results in the research, often based on results obtained only for very limited geographic areas or periods of time. There are also a number of questions that have not yet even been addressed. Despite those problems, however, there do appear to be some basic conclusions we have reached that can be taken as a starting point for future research:
- Of all of the weather variables measured, only higher temperatures, often augmented by higher humidity, show a consistent and robust relationship to crime.
- In the United States there are pronounced seasonal patterns for rape, assault, burglary, and larceny, with all of these crimes increasing during the summer months. Other nations also display seasonal patterns for specific crimes, but they do not always have the same summer peak seen in the United States.
- Both murder and robbery show regular monthly patterns, but not along seasonal lines. From this, it is important to understand that the impact of weather, whether seasonally or day by day, on any population is mediated by the culture, the social and economic status, and the demographic structure of that population.
- The most effective model explaining the observed relationship between weather or season and crime is routine activities theory. Activities common to hotter weather or hotter seasons tend to directly or indirectly influence the probability of a convergence of motivated offenders, suitable targets, and reduced guardianship. Interactionist models that consider changes in stress produced by differing behavior patterns occurring in different weather situations or seasons also show promise in explaining changes in personal crime.
- Climate as an explanatory variable for crime differences or the alleged criminality of any population has been largely discounted.
It is inherent to the nature of science that conclusions that are accepted at one point in time will change as more research is conducted to test those conclusions. Criminology scholars need to continue studying the relationship of weather and homicide in order to sophisticate theory, to test previous results with more accurate data and better analytical techniques, and to produce policy recommendations that can help reduce crime.
There is a need to improve criminological theories that address the relationship of weather and crime. Criminology needs better integration of the existing theoretical models, and there is a need to continue research that specifically tests theories of the weather-crime relationship. Some studies have done this, but future research needs to develop very specific testable propositions that would enable us to integrate (or to distinguish between) two or more theories and then perform the research necessary to test those propositions.
We now have ever more complex and detailed data. Where early research often had only the number of crimes reported in some area over some period of time and, at best, daily weather data for those areas and times, modern technology can now secure hour-by-hour weather and crime data for any number of places over long periods of time. However, only improvements in theory can lead to more carefully selected data and more precisely targeted analysis. The research conducted from the 1970s through the 1990s began to explore the possibilities. Now, in the 21st century, criminology has enough consistent findings, much more sophisticated analytical techniques, and equipment capable of applying these techniques to massive data sets.
With all of this, further research is needed across broader geographic areas and over longer periods of time. We are becoming aware that weather “works” in interplay with temporal data, for example. We know that weather conditions can change the impact of time of day or day of the week, and we suspect this applies to major holidays as well. If some assumptions of interactional stress are correct, we need to begin to examine these interactions in more detail, including examining whether these weather and time interactions are different in hotter versus cooler climatic areas.
It is also significant for the future study of weather effects on crime that we are controlling our weather environment far more than we used to. We air-condition our homes, our cars, our businesses, and our places of entertainment. The data may be hard to obtain, but criminologists need to begin to consider what impact that has, particularly as it spreads (or fails to spread) to subgroups in our society, specifically, the poor. If these changes allow most people to mitigate much of the impact of increased heat and concomitant stress, but are not available to the poor, what impact will that have on crime rates in those neighborhoods in which crime is already a significant problem?
In this regard, criminologists need to begin to consider ways to apply the knowledge obtained. We cannot change the weather—at least, not yet. However, if we understand the impact of weather conditions on different areas, different times, and different populations, then we should become better able to prevent, or at least reduce, increases in crime resulting from this impact. It is possible that some of the most basic understandings of how temperature affects people’s routine activities or increases their levels of social stress, with resulting increases in crime, might enable us to act to head off some of those increases. We cannot yet put climate-controlled weather domes over our major cities, but with well-developed theory leading us to examine detailed data, we might be able to find some ways to address the weather-crime interaction with the technology we now have.