When the temperatures rises, crime and aggression increases–to a point. Beyond a certain temperature, violent crime declines, says the Washington Post. No one knows exactly why baking heat prompts criminals to turn meek. But when scientists tracked the connection between the temperature and 911 calls for violent assault in Minneapolis and Dallas, they found a curvilinear relationship — crime rose up to a point, then fell — making the shape of an inverted “U.”
Temperature is not the only factor that affects fluctuations in the crime rate. The time of day, day of the week, population density, even whether a major holiday is underway, all have effects on crime. The temperature effect is overlaid on all these other factors, said Ellen G. Cohn, a criminologist at Florida International University. Air-conditioning plays a role, too. Removing the effects of sky-high heat in homes and office buildings appears to reduce aggession.