Does your system sound better in the winter?

I've noticed the same phenomenon with my system over the years (more than 20). I found its much worse if you are playing vinyl but this is relatively easy to guess why. The phono cartridge is more susceptible to environmental changes such as temperature and humidity. Most manufactured items are specified to perform optimally at 20 degrees C room temperature. So the wilder the fluctuations of operating ambience so should the equipment's performance I guess.

the only thing i know that if outside on the street is 100 i have to turn on A/C and despite i have quite quiet model it's still noisy and swallows details which doesn't happen in winter time. in the winter time i used to have a very noisy heater but now this issue also had bee resolved.:^)

The blue light on my amp doesn't light up (or it lights very dimly) on days like the ones you mention...not enough power, I suppose. The amp still works, but it's obviously receiving less power than it should. I'd comment on the sound quality, but I can't hear a damned thing with all of the fans and air conditioners running.