Joe Hunt wrote:

I have been thinking about filing a paper on such an occurrence, it
happens annually if you have not noticed. Examinations start = weather
heats up ! Does this warrant any scientific backup !?

Not true here - exams have been going on for the past three weeks. Sod's
Law has it that because last year was my last year of exams, the
weather's been grim so far! And of course it's going to brighten up next
week - I'm off on holiday then!

Jonathan
Canterbury, Kent