Count us in -- Feb 26-March 8. Our third trip in a row at this time of year. I agree with what everyone had posted. It doesn't hurt to check the weather forecast before you go, in case an unusual cold snap or heat wave is coming, but mornings often require sweatshirts and maybe windbreakers on top (with shorts, sneakers, and socks), but by afternoon usually they are down to shorts and t-shirt, and then at night the longer layers go back on.
As for rain, I would bring iian gear for any time of year in Florida, although laet Feb/March is not nearly as wet as high summer.