An analysis by the New York Times of rainfall and homicides for the last six years shows that when it rains substantially in the summertime, there are fewer homicides. When there was no precipitation, there was an average of 17 homicides every 10 days. But when there was an inch or more of rain, the average dropped to 14. Vernon Geberth, a former Bronx homicide squad commanding officer, said that when there was a downpour, the police would joke, “The best cop in the world is on duty tonight.”
Some criminologists caution against reading too much into the differences. Ellen Cohn of Florida International University, who has examined links between weather and crime for more than two decades, said the impact of rain on crime was “not much.” She said rainfall tended not to strongly predict homicides. Studies have found that other crimes, like aggravated assault, went down when there was rain. Cohn said one reason might be that assaults more often involve strangers, and rain reduces the chances that people who do not know each other will encounter one another.