World Resorts USA Key West Weather

Key West weather in August

Weather in Key West: August

Average day temperature: 87.4°F
Average night temperature: 83.2°F
Sea water temperature: 87.1°F
Number of sunny days: 11 days
Day length: 12.6 - 13.3 hours
Number of rainy days: 7 days
Precipitation totals: 3.9 in.

Air temperature in August, °F

Show year:
2025
2024
2023

The highest day temperature during August of 2025 was 88°F. At the same time the lowest night temperature was 82°F. Daily and nightly averages during August were 86.9°F and 84.3°F.

Sea water temperature in Key West in August, °F

Show year:
2025
2024
2023

The average sea water temperature in August of 2025 was 88.8°F. The highest and lowest sea temperatures during the month were 90.7°F and 86.9°F.

Sunny, partly cloudy and cloudy days

Mostly all days in August are partly cloudy but sunny or cloudy days are also possible.

Precipitation total in August, in.

Precipitation total value in Key West in August is 4.3 in. Other months of the year show relatively similar values.

Wind speed in August, mph

The average wind speed value in August is 10.6 mph It makes August one of the least windy months of the year.

Average sunny hours

This chart shows average number of hours during the day when sunlight can reach the ground. It depends on day length and cloudiness during the day. The average number of sunny hours in August is: 7.4.

Best time for vacation in Key West

Sunniest months:
May 16 days
March 16 days
April 16 days
Warmest months:
August 87.4 °F
July 86.9 °F
September 85.8 °F
Warmest sea temp:
August 87.2 °F
July 86.6 °F
September 86.1 °F
Coldest months:
January 72.1 °F
February 74.0 °F
December 75.4 °F
Rainiest months:
June 7 days
August 7 days
September 6 days
Windiest months:
November 14.7 mph
December 13.9 mph
January 13.8 mph

Key West on a weather map

Key West
+75°F
W 13 mph
Feels like: +81°F
Precip.: 0%
Places in USA:
Name
°F
+30°F
+75°F
+75°F
+41°F
+52°F
+70°F
+77°F
+70°F
+21°F
+54°F
+46°F
+61°F
+61°F
+45°F
+3°F
24 Hours Forecast
Key West
Local time: 02:49
December 05, friday
0300
75°F
W
13 mph
0600
77°F
W
11 mph
0900
75°F
W
7 mph
1200
75°F
W
11 mph
1500
77°F
W
12 mph
1800
79°F
NW
11 mph
2100
77°F
NW
10 mph
December 06, saturday
0000
75°F
NW
11 mph
Units of measurement: °C / °F