Weekend heatwave may cool off gun violence in Philly

Recent crime data shows Philly sees more shootings when temperatures rise above 85 degrees. But excessive heat can have the opposite effect. (Emma Lee/WHYY)

Recent crime data shows Philly sees more shootings when temperatures rise above 85 degrees. But excessive heat can have the opposite effect. (Emma Lee/WHYY)

Philadelphia is going to be dangerously hot this weekend, with temperatures expected to hover around 100 degrees but feel even worse. 

One possible silver lining: safer streets. 

Recent research shows there’s a strong correlation between weather and gun violence. Cold days tend to mean less gun violence. Hot days tend to bring more, to a point.

In Philadelphia, the gap between those poles was significant between 2015-2018, according to crime data crunched by AH Datalytics, a New Orleans-based data analysis company. 

Days below 50 degrees averaged 2.6 shootings, while days that hit at least 85 degrees averaged 4.4 shootings, the research showed. 

The caveat, said founder Jeff Asher, is when the forecast is so brutal the National Weather Service issues an excessive heat warning, as it did this week for big swaths of the Midwest and East Coast. 

“The data typically shows that if you get above 95 degrees, it should have a slowing effect on gun violence — that it’s essentially too hot for people to go outdoors and be engaged in activities that lead to gun violence,” Asher said. 

Typically, but nowhere near definitively. While days with boiling temperatures aren’t unusual in Philadelphia, they’re usually not numerous. 

“It’s not over 95 degrees often enough in a place like Philadelphia to really say with confidence what it’s going to do,” Asher said. 

That squares with Scott Charles, Temple University Hospital’s longtime trauma outreach coordinator. For the past 15 years, it’s been his job to stay keenly aware of the ebb and flow of gun violence in the city.  While it can spike with warmer weather, he said it’s largely unpredictable — “evergreen.” 

In fact, some of the most violent days he can remember were during the winter, including the Thursday Officer Robert Wilson was shot and killed during an armed robbery inside a GameStop in North Philadelphia. 

“I just remember being out with a snowblower and turning on my phone to find all of these text messages to find all of these trauma alerts,” Charles said. 

The Philadelphia Police Department declined to comment for this story, but in May, Commissioner Richard Ross announced that dozens of more officers would be pressed into patrol duty this summer, including those normally assigned to administrative work. 

This past weekend, in the wake of a shooting at a busy community cookout in the Overbrook section of the city, Mayor Kenney asked the Parks and Recreation Department to increase security at all permitted events for the rest of the summer. 

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