Then there’s the slight problem of the USSR where more people died a violent death than anywhere else on earth in the 20th century ... I do accept though that heat will give more opportunity for anyone prone to violence to act on their urges, that is fairly obvious anyway and doesn’t need a study. I don’t have any numbers handy but would be willing to bet there’s more gang-related deaths in Chicago in summer than in winter. But the cause and effect is likely more the absence of cold than the presence of heat so I would not be so willing to guess how spring and autumn compare to summer, probably not much if any difference. Once the outside temperature is warm enough to hang about in the outdoors or drive around with car windows open, the violence is more likely to happen. So when you get past that limiting thresh-hold the rates may not increase much. Extreme heat might actually lower the rates, gangstas would prefer to chill in the A/C of a bar or mall probably.