does temperature affect speaker performance?

I can't be certain but years ago I had a Magnepan 1D. I live in south Florida and I have no doubt that it sounded better in the winter when the humidity was low and the temperatures were lower than in the summer. No idea if cone speakers behave the same. Right now I have Merlins and I think they sound the same all year.

Maybe your ears are affected by the weather?

Dynamic driver speakers run pretty hot after just a few seconds play - so I doubt if external weather would make much of a difference.

I have Maggies, and have heard that humidity affects them substantially. My experience in humid NC seems to support that.