Anytime is a good time to visit. Yes, they get some "cold" days in December and January...maybe even in the low 30's which is rare and usually only lasts a few days. And yes, they get some real scorchers...sometimes close to 100 degrees F, but these are few and far between and usually come in August.

Sea breezes usually keep it a comfortable 60-70 in the winter and mid 80's in the summer. But you want perfect? Go to St. Petersburg in the Spring....maybe in April or May. At that time of year, most of the "snowbirds" have returned north and there is less traffic; the lovely purple jacaranda trees are in their glory; skies are a beautiful cloudless blue; and it is wonderful to be outside enjoying all that Paradise has to offer. 

The Weather Channel Website

Accuweather Website