Analysis of more than 50,000 suicides in England and Wales between 1993 and 2003 showed the suicide rate rose when average daily temperatures topped 18C. The study appears in the British Journal of Psychiatry and is mentioned on the site of BBC News.
The researchers discovered that a rise of 1 degree C (celsius) above 18 C increases the suicide rate with 4%.
1. Higher degree of aggression and impulsivity due to the hot weather.
2. The use of more alcohol in hot weather
If the hot weather starts suddenly the risk is higher than when people can adapt to the higher temperatures. Overall three-quarters of all suicides were by men and the largest number of suicides took place on Mondays. No spring or summer peak in suicide was found.