With an annual average temperature a beautiful 80º F, it's no wonder that the Florida Keys are known for their year-round weather. It truly is better in the Keys! The Florida Bay to the north and the Atlantic Ocean to the south - these islands enjoy the luxury of cooling waters and refreshing tropical breezes. Winter-weary northerners flock down each winter to enjoy sunshine and warmth while Floridians come down from the mainland largely in the spring and summer months.
Let's give you some background on the weather in the Keys. The all time record high in Key West was 97º F (36º C) back in 1880 with the all time low of 41º F (5º C) in 1981. The height of summer has an average high of 89º F (32º C) with water temperatures in the mid-80's, while winter months typically temperatures stay in the 70's and low 80's with water temperatures in the low-70's. The official start of hurricane season is June 1st and ends November 30th. August through mid-October seems to be the highest months for storms (if any occur) so with that in mind…Summer's end is almost certainly the down time in the Keys with the crowds returning at the end of October for Key West's Fantasy Fest and continuing throughout the remaining months.