Measurements:
°C
°F
Key West
88°F
W 6 mph
Feels like: 96°F
Precip: 7%
World Resorts USA Key West Weather

Key West Sea Water Temperature

Current Sea Water Temperature:
+87.4°F
Maximum Sea Water Temperature in October: 91.0°F
Minimum Sea Water Temperature in October: 81.2°F
Average water temperature in October: 86.8°F

Sea Water Temperature for the Last 10 Days:

October 05 87.4°F September 30 89.8°F
October 04 87.6°F September 29 90.0°F
October 03 87.6°F September 28 90.4°F
October 02 89.8°F September 27 90.2°F
October 01 90.0°F September 26 90.0°F

When is the Warmest Sea for Key West?

According to our data for the last three years for Key West the highest average sea water temperature was in August, July and September.

Average Water Temperature by Month, °F

Sea Water Temperature in August

Select Year: 2026 2025 2024

The average sea surface temperature in August 2026 for Key West was 93.1°F. The maximum and minimum values were 91.2°F and 95.0°F respectively.

Sea Water Temperature in July

Select Year: 2026 2025 2024

The average sea surface temperature in July 2026 for Key West was 92.8°F. The maximum and minimum values were 91.6°F and 94.4°F respectively.

Sea Water Temperature in September

Select Year: 2026 2025 2024

The average sea surface temperature in September 2026 for Key West was 92.0°F. The maximum and minimum values were 89.8°F and 93.8°F respectively.

Best Time to Visit Key West
The most sunny months:
May 17 days
March 16 days
April 16 days
The most warm months:
August 91.5 °F
July 91.0 °F
September 89.6 °F
Warmest sea temperature:
August 91.4 °F
July 90.8 °F
September 90.2 °F
The most cold months:
January 74.4 °F
February 76.3 °F
December 78.2 °F
The most rainy months:
June 7 days
August 7 days
September 6 days
The most windy months:
November 14 mph
December 14 mph
January 14 mph

Key West on the Weather Map

USA Resorts:
NAME
F°
Boston +58
Chicago +62
Hawaii +82
Houston +86
Las Vegas +92
Los Angeles +100
Maui +74
Miami +88
Myrtle Beach +70
New York +62
San Diego +84
San Francisco +66
Santa Monica +94
Sarasota +84
Washington +64
24 Hours Weather Forecast
Key West
Local time: 19:46
05 oct, monday
2100 88°F
W
6 mph
06 oct, tuesday
0000 86°F
W
8 mph
0300 86°F
W
8 mph
0600 86°F
NW
9 mph
0900 86°F
NW
7 mph
1200 86°F
NW
6 mph
1500 86°F
NW
6 mph
1800 86°F
NW
4 mph