Why does crime increase in the summer?


Nathan Wilson | Reporter
Natchitoches Chief of Police Nikeo Collins points out the summer season in Natchitoches isn’t as quiet for law enforcement as he would like. “During the summertime, even though students leave and we have less population and you notice traffic’s relieved, it should be a time where we can just rest and relax. We can’t though,” he says. Collins explains that Natchitoches experiences an annual spike in crime that coincides with the arrival of summer.
Cities nationwide experience the same spike in crime each year, leaving law enforcement authorities, researchers and policy makers searching for an explanation. Several factors that are commonly suggested include higher temperatures, longer daylight hours and the end of the school year.
Among environmental factors, decades of research reveal a strong correlation between higher daily temperatures and criminal activity. Other factors such as humidity, sunshine and windspeed show little effect on the prevalence of crime.
The fastest increase in crime rates occur as the weather changes from cold to mild. Most types of crime continue to increase with rising daily temperatures before peaking as the weather becomes hot. Crimes such as theft and disorderly conduct, for example, gradually decline again as outdoor temperatures surpass 90 degree Fahrenheit and people again seek shelter from the heat.

This article published in the July 14, 2022, print edition.

Collins explains people spend more time outside when the weather is pleasant which presents criminals with additional opportunities to observe unsecured property, encounter unwitting victims or break into unattended homes. He explains that something as simple as rain can dramatically reduce the amount of crime reported to his office. “I get excited when it’s colder or we have wet weather, because we might have burglaries that take place because people use that as a guise, but not as much,” he says. “It stands out when someone’s out and they’re walking around and it’s pouring down rain or it’s super cold, it’s like ‘what are you doing’, but when it’s warm people are going to do that.”
As outdoor temperatures become uncomfortably hot, people once again spend more time indoors and many types of crime begin to decline. Violent crime, however, is a dramatic exception to this tendency. “You have a propensity for more agitation,” says Collins. “Temperatures make individuals flare more.” He offers some scenarios that lead to violence during the summer. “More people go ‘you looked at me the wrong way’, or either they can’t go home because it’s super hot there or they got kicked out because they weren’t doing something they were supposed to do,” he says.
A physiological explanation for increased violence is that the discomfort caused by high outdoor temperatures acts as a stressor and alters the brain’s chemistry to make people more aggressive and irritable. As the days become longer and hotter, tempers become short and violent crimes increase even as other forms of crime taper off.
Extremely hot weather should also cause violent offenses to begin declining as people shun public interactions to seek shelter, yet there’s no agreement on when the weather becomes too unbearably hot to commit a violent offence. Some researchers suggest violence should begin to taper off at temperatures as low as the high seventies to mid-eighties, but comparisons between cities indicate that hotter regions of the U.S. typically experience higher rates of crime despite reporting temperatures much hotter than the expected peak.
Police Chief Nikeo Collins

A 2018 study by the National Institute of Health of more than a decade of crime in Chicago suggests that many violent offenders become active later in the evening during the hottest months of the year. This data suggests that hot weather causes people to begin socializing more at night when the weather is cooler which leads to more violent crime.
Teenagers and young adults already exhibit a tendency to go to sleep later than older adults and shunning the outdoors during the hottest part of the day leaves them feeling restless in the evening. Collins notes that the end of the school year leaves many young people lacking both daytime structure and nighttime supervision. “A lot of the burglaries that are taking place are juveniles out and about after curfew. Their parents don’t know where they’re at,” he says. “Last year we had a homicide and there were two juveniles involved because they were out at night. It was two or three o’clock in the morning.”
Longer daylight hours and higher temperatures also cause people to suffer from lower quality sleep during the summer, which is also linked to increased impulsivity and aggression, which contribute to criminal behavior. In an effort to identify a link between sleep and criminal activity, a company called The Sleep Judge funded a study of hourly crime data from 10 American cities that concluded that most violent crime occurs at night while property crimes occur more frequently during the day. They noted that reports of sexual assault peak around midnight, aggravated assault at 10 p.m. and homicide at 9 p.m. Among non-violent crimes, only DWI’s occur more frequently at night.
While the Natchitoches Police Department responds to reports of crime year-round and at all hours, it can’t do anything about the high temperatures and long days that are a fact of life during the summer. For the youth, it enforces curfew, but officers can’t supervise them during the day or ensure they get adequate rest during the shorter nights. Collins instead recommends seeking solutions within the community. “Idle hands are the devil’s playground,” he says. “That’s why it’s good to have programs like the Boys’ and Girls’ Club: something that we can structure. It keeps them distracted. It keeps them out of trouble. It helps teach them skill sets that they need to function in society and hopefully keeps them out of trouble.