(Summer) Time for murder: Is there a link between increased temperature and homicides?

Abstract

A number of studies investigating the link between weather and homicides indicate that weather has an effect on the occurrence of murder. These studies argue that the weather and its changes can act as stressors, especially for individuals who are highly sensitive to stress and thus the weather can have both physiological and psychological effects on human behaviour. The aim of the present study is to examine the relationship between temperature (daily Tmean and Tmax) and the incidents of homicides in Central and Northern Greece. A total of 137 homicides were registered in the investigated area between 1995 and 2004. The results revealed that more than 30% of the registered homicides occurred on a day with a Tmean> 25° C and that about 45% of the registered homicides occurred on a day with a Tmax> 25° C while half of them were committed with a Tmax> 30° C. The results showed a higher correlation of the number of homicides with Tmax than with Tmin. Our findings are in accordance with other studies, which showed an association between crime and increased temperature, as well as with theories of criminality, according to which negative affect and violent acts increase as temperature rise.