Humidity

I am sure it's been analyzed in some scientific study here or there, if it's not already been revealed in academic report.

I mean, the fact that people are touchy when the weather gets under their skins.

Your wife yelled at you for no reason, cars at your back honked for the slightest wait, cars rudely cut in front you, cars speeding, sirens wailing in, sirens wailing out, even your cat seemed to hold a grudge against you, only she's too busy napping to take it out on you.

Spring is occasionally nice here, like when you go for a night cruise with the windows down. But most of the time, rain and sun combine in such a bad way that you swear you want to wring the air dry like a dripping towel.