I have often wondered this and I think it varies soooo much from person to person.
I always get sick in feb/mar due end of cold/flu season here in MI. I also hate the change of seasons, not necessarily the season itself just when it is chaning like crazy bothers my sinus's.
The main thing I hate is rain, if I had to live in seattle I would be misserable.
I thought moving to florida would be good as less changes of season however hubby pointed out how damp and humid it is which really affects me (more before xolair) so he had a point there too.
What we decided was if we were going to move I would go stay there for at least a week before decidding 'just to see'. If your daughter is thinking of going somewhere she may want to try that. Given her good health she should fair ok, I would think, either way.