We had a really pleasant week in the Keys December last year. I don't know how that translates to February, but we were able to swim each day.
We were in JPSP late Dec last year and hardly anyone was in the water due to a cold front. The next week we were in BHSP and it was much nicer and we were swimming. Keep in mind I am from NC coast and prefer 80 degree or better water to swim in. I see people from up North swimming here in May and enjoying it. Just depends on what you like or are used to I guess. I think water temp was in 72-74 range when we were in the Keys in Dec. last year. That is not bad to me if the sun is out and not a lot of wind. The first time we went to BHSP was in late March / early April and it was perfect for me, like bath water.
