The temperature in Casey Key is so perfect that the changing of the seasons often go unrecognized. Casey Key enjoys a sub-tropical climate in which extreme summer and winter temperatures are mellowed by the presence of the Gulf of Mexico.
The average annual temperature is 75 degrees, while the waters of the Gulf of Mexico warm to an August high of 89 degrees, to a winter low in the 70's.
Average Temperatures throughout the year:
December through February 72.6 degrees
March through May 80.4 degrees
June through August 89.6 degrees
September through November 82.6 degrees