Average Ocean Water Temperatures at Key West

The table below lists typical water temperatures for each month of the year in the ocean off Key West in Florida.

The temperatures, given in both degrees Fahrenheit and degrees Celsius, are long-term averages.

The water at Key West is warm enough for swimming all year round.

The ocean reaches its warmest point of the year in July and August when the temperature averages 87 degrees Fahrenheit (31 degrees Celsius).

The coolest month is January, when the temperature is usually around 69 °F (21 °C).

Key West's average seawater temperature
Period °F °C
January 69 21
February 70 21
March 75 24
April 78 26
May 82 28
June 85 29
July 87 31
August 87 31
September 86 30
October 82 28
November 76 24
December 72 22
Annual Average 79 26

National Oceanographic Data Center. NODC Coastal Water Temperature Guide (CWTG).

Florida Ocean Temperatures
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