I live in Tampa bay area. We see the same thing here. You will leave the windows in you car cracked to release the heat because the sky is perfectly clear. Then 20min's later you have run out and close the window because you have a thunderstorm coming. In my job I talk to people from other parts of the country. They often say they are afraid of being in Florida because of the hurricanes. At least you know when a hurricane is coming. The real danger is lightning. You never know when lightning may hit. It can kill people walking down the street or it can fry your TV.