I'm the same way concerning "reverse seasonal affected disorder" or whatever it's called. In the Summer it's so brutally hot and humid here that it's just draining. Even at night it never cools off, and I guess it doesn't help that I live in Downtown Dallas. Concrete for miles, keeping the temperature from going below 85 degrees for weeks and weeks on end in the summer (according to my building's weather thing, at least).
We're still above normal here, well above 80 in the day and sometimes over 90, but that's easily bearable compared to 100+ with humidity. The nights have been nice even after the warmer days. Low seventies in these parts is jacket weather when it first hits, haha. Some of the outlying suburbs have already gotten into the 40's a couple times this fall.
But anyway, after work and on weekends I'm basically a shut in during the summers. With the pollution, heat, and humidity it's just miserable (to me). In the fall and winter (we don't really have a true winter but you know) I finally come alive. It's funny to gain weight in the summer and lose it during the holidays, haha. Probably not uncommon around here, though.
I really miss living in California and Virgina. In Virginia it could get pretty cold (it's no Minnesota, I know, but for a Texas guy it gets cold there, ok) and I loved it. In California it would get really hot, but it was dry, and if you wanted cooler weather you could just go to the beach. I don't know if all of CA is that way, but LA was. I lived in Alhambra where it would get pretty warm, but in Santa Monica it would always be a lot cooler. And the nights were always cool even, it seemed to me. I remember my first trip out there to visit a friend. It was 104 degrees at the airport when we took off, and 65 when we landed a few hours later in LA. That was awesome.
But back on point, I know being bottled up is bad for my anxiety, and I'm sure it is for others as well. Even though I'm inside right now, I COULD go out and be comfortable and just knowing that is enough. I guess it's different for agoraphobics, though.