How do rising temperatures affect U.S. crime rates?
Canceled flight announcements. Endless honking during road construction season. Ice cream truck ditties on repeat.
These far-from dulcet sounds of summer can drive us to the edge of reason, especially while driving. Business-security camera, police CCTV, and convenience store camera system footage consistently reveal how summer heat makes Americans hot under the collar.
While we experience the very real effects of road rage, do we see red more often in summer? When the mercury rises, does the increase in temperature send tempers into overdrive?
Researchers find that violent crimes tend to increase in warm weather, attributing our red-hot behavior to two well-established theories.
The routine activity theory claims violent crime increases as temperatures rise because heat affects our habits, activities, and destinations. From going to the beach to drinking in packed beer gardens, we interact, chat and mingle with more people in summer than we do when it’s cold. With more people outside on hot sunny days, people encounter more reasons to get annoyed. And in the worst-case scenarios, their tempers flare and conversations end in confrontations.
Warm weather also opens the door—or window—for crimes of opportunity, business security cameras can document it. With more people leaving windows cracked or leaving town altogether for a cool breeze on their faces, it’s easier to gain entry into homes, garages, and parking lots. And it’s likely they are taking more than inspiration for interior design and the latest in automobile detailing.
And when summer break starts, more young people are out and about. Other studies note that men younger than 25 are more likely to commit crimes than older men. So, if they don’t have a job slinging ice cream, stocking shelves, or guarding pools, grandma’s catchphrase rings true: “the devil finds work for idle hands.”
The other theory that can explain hot-headed behavior is the temperature aggression hypothesis. This states that the effects of heat are both direct and indirect, with higher temperatures influencing people’s moods. The TL;DR? We can take irritation to eleven, and under the right (or more accurately, wrong) circumstances become quite aggressive.
Heat-wave-equals-crime-wave headlines, often illustrated by footage from the wireless camera systems businesses use, dominate the news cycle during the summer.
According to the U.S. Department of Justice, crime can increase up to 35% during the summer in the United States. In a 2014 study on seasonal crime in the U.S., researchers found that the increasing crimes in question were violent crimes, like rape, assault, and murder and property crimes like theft and burglary. Vehicle theft and robbery rates remain the same, no matter the weather.
And researchers from Governing found that northern states like Minnesota and New York saw the most increases. It’s a nationwide trend; Its analysis also revealed that each of the 42 police agencies reviewed recorded average increases of greater than 20% compared to other times of the year.
Chicago often makes the news as violent crime in the Windy City spikes during the hotter months. The University of Chicago’s One Summer Chicago reports there about twice as many shootings on days over 85 degrees as there are on days under 50 degrees.
Across the country, from Baltimore, Cleveland, and Detroit to Minneapolis, Denver, and San Antonio, local leaders and police recognize that heat plays a role in the crime increase, but is not the only factor. Police and politicians are working to combat the summer crime season by employing different strategies as well as tested tactics this summer.
Yet this problem dates back centuries, according to researchers from the University of California.
A comprehensive 2013 study surveyed 60 diverse, quantitative studies spanning a range of disciplines including archaeology, criminology, economics, geography, history, political science, and psychology. The research uncovered a consistent link between higher temperatures, reduced rainfall, and drought, with a corresponding rise in violence. This pattern was evident in individual acts of violence, like domestic abuse and assault, and even more markedly in group conflicts.
This study presents more complex issues for researchers to consider, but anyone who endures a heat wave without long-term relief knows this is a story as old as time.
“When people are hot, it makes them cranky,” Brian Lickel, a social psychologist who is on the faculty of the Psychology of Peace and Violence program at the University of Massachusetts told Scientific American. “It makes people more prone to anger, it makes people more frustrated, and it makes decision-making more impulsive. And that can lead to altercations that escalate to more extreme levels of aggression.”