The weather is hot, but not stifling...plenty to do. In fact, Places Rated Almanac put Tampa in the top 5, I believe.
First word of advice: Pinellas county is a major no-no if you have kids in public school. They're still in the process of living up to an integration consent decree, and your kids stand the possibility of being bussed all over the county...
Hillsborough county is nice, the schools overall are quite good, and you're close to churches/shopping/entertainment, etc.
We've just bought a house in Plant City (Strawberry capital of the World), just east of Tampa proper--it's right off I-4, one of the better freeway corridors in the area (major widening project recently finished). We're in a rental home until we sell our house in Texas, and we spent every weekend for 5 months (really!) looking at neighborhoods, and we couldn't be happier with what we've found. Nice, down-to-earth people, slightly slower pace than the big city, but just a short hop to town. BTW, there are lush agricultural areas near here...been enjoying some of the best fruits/veggies I've EVER had.
If it had not been so far from my wife's office, we'd have given some serious consideration to the Lakeland/Winter Haven area...just drove through, but it looks nice.
So is Seminole County, FL - it's horrible!