Hi
APJH,
climate fibromyalgia
climate peripheral neuropathy
For many, it's not so much the climate, but the
changes in weather that affect pain & other symptoms the most, so those who live in areas where it can be said, "
If you don't like the weather, stick around -- it'll change!" may suffer the effects of climate more. A stable climate with few/mild changes, regardless of climate type (hot/warm, cold, wet, dry) may be less painful than one changing often throughout the seasons/year. (
If you find someplace like that, lemme know! 
)
That said, common advice to retirees/soon-to-be-retirees considering relocating is to rent for a month (or more) during the most inclement season in any prospective destinations before picking up stakes and making a permanent move. I think this is good advice to anyone considering relocating for just about any reason -- especially health reasons.

YMMV.
There are also many
other criteria/factors (than climate) to be considered in longterm/permanent relocation (e.g. economy, employment, cost of living, access to medical care/services, transportation, education, political climate, quality of life, crime, taxes, more...)
Doc