How can a temperature indicate …
Both hot and cold, and not be lukewarm?
Comparison of high and low temperatures in Naples and Gainesville
Answer: Yes, it’s called the 70° Rule. Here’s how it works: Any day that the daytime high doesn’t rise above 70° F is considered a winter day in Florida. I know that doesn’t seem “cold” by the normal standards of the Continental North, but for Florida it’s a relatively rare event. In Naples, it happens on average about 18 times per year.
Come the summer half of the year, the same 70° line serves as the threshold for ushering the afternoon buildup of clouds (and pounding rains), except it’s flipped: nighttime lows above the 70° line (not daytime highs) is the measuring stick. On average, Naples has about 140 such days (i.e. nights) each year.
In summary, we can thank our lucky stars for the 70° line in south Florida. How else would we ever discern between summer and winter?