There's more to tough weather than cold winters, and it depends what you like and what you hate. Hilo gets huge amounts of rain. Orlando has lots of lightning. Swampfox moved to Laramie in part because he likes the weather!
If the group of voters consisted of distance runners, I think Houston would be a lock. Even in St. Louis, I've been known to do my summer long runs at 1AM. Houston is an order of magnitude less pleasant in July.