This calendar chart shows the history of cold nights in Naples Florida from 1942 to present as measured at Naples Airport (APF). Gray dots indicate nights that the low temperature dropped into the 50s, green dots the 40s, blue dots in the 30s, and red dots below freezing. Do you see the red dot in January 2009? That's the year that a thin veneer of ice formed on a water body in Big Cypress National Preserve. I have photographs to prove it (even if I didn't step out on the slick surface to confirm ice thickness -- about a millimeter or two).