As others have said, layers will be good. Many non-Floridians underestimate FL cold. It's different. 40 in FL isn't like 40 in New England (due to the humidity, I guess, is what people say). It's uncomfortable, it's not that crisp cold feeling.
But if you are dressed right, you should be okay. If I were a local, and I had plans to play at the parks this weekend, I would be tempted to stay home. I'm working both days, sort of dreading the parts where I'll be outside and the walk into work.