Well, certainly not 95 degrees!!!! I'd do Phoenix December-March. And March in Chicago, the windy city? I live about 6 hours from Chicago and it's usually snowing here, we get similar weather as they do, it's usually still in the 30s and 40s. Atlanta in March is beautiful, but late April to May it's hot enough to not do anything but hang out at the pool. It's a fun city but I don't want to pour sweat while I am out and about.
But they will keep doing what they do and people who don't mind crappy weather will still attend. Maybe one of these days they will figure out that they could charge more and get more people to come by changing up the venue to a more pleasing climate.