Measurements:
°C
°F
Key West
80°F
W 5 mph
Feels like: 84°F
Precip: 0%
World Resorts USA Key West Weather

Key West Sea Water Temperature

Current Sea Water Temperature:
+77.8°F
Maximum Sea Water Temperature in February: 81.6°F
Minimum Sea Water Temperature in February: 65.8°F
Average water temperature in February: 76.0°F

Sea Water Temperature for the Last 10 Days:

February 21 77.8°F February 16 73.4°F
February 20 76.0°F February 15 71.8°F
February 19 75.2°F February 14 71.2°F
February 18 74.6°F February 13 70.6°F
February 17 74.4°F February 12 69.4°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: 2025 2024 2023

The average sea surface temperature in August 2025 for Key West was 93.1°F. The maximum and minimum values were 91.0°F and 95.2°F respectively.

Sea Water Temperature in July

Select Year: 2025 2024 2023

The average sea surface temperature in July 2025 for Key West was 90.8°F. The maximum and minimum values were 89.0°F and 92.2°F respectively.

Sea Water Temperature in September

Select Year: 2025 2024 2023

The average sea surface temperature in September 2025 for Key West was 91.0°F. The maximum and minimum values were 89.2°F and 93.6°F respectively.

Best Time to Visit Key West
The most sunny months:
May 16 days
March 16 days
April 16 days
The most warm months:
August 91.6 °F
July 91.0 °F
September 89.7 °F
Warmest sea temperature:
August 91.3 °F
July 90.6 °F
September 90.1 °F
The most cold months:
January 74.4 °F
February 76.6 °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
Chicago +28
Hawaii +70
Honolulu +70
Houston +74
Las Vegas +42
Los Angeles +48
Maui +66
Miami +86
Miami Beach +78
New York +42
San Diego +50
San Francisco +46
Sarasota +74
Tampa +78
Washington +48
24 Hours Weather Forecast
Key West
Local time: 11:03
21 feb, saturday
1200 80°F
W
5 mph
1500 80°F
W
4 mph
1800 80°F
SW
3 mph
2100 76°F
W
3 mph
22 feb, sunday
0000 74°F
N
2 mph
0300 74°F
NE
3 mph
0600 72°F
S
6 mph
0900 72°F
SE
1 mph