Current sea water temperature:
+88.5°F
| Minimum sea water temperature in September: | 89.6°F |
| Maximum sea water temperature in September: | 82.8°F |
| Average sea water temperature in September: | 86.2°F |
| more information | |
14 days
forecast
forecast
| Key West |
monthly
weather
weather
| Key West |
Sea water temperature for the last 10 days:
| September 14 | 88.5°F | September 9 | 88.7°F |
| September 13 | 88.3°F | September 8 | 88.7°F |
| September 12 | 88.3°F | September 7 | 88.3°F |
| September 11 | 87.8°F | September 6 | 89.4°F |
| September 10 | 89.1°F | September 5 | 89.4°F |
Monthly sea water temperature, °F
When is the warmest sea in Key West?
Based on the data about daily sea water temperature for the last three years the warmest sea in Key West was noticed in August, July and September.
Monthly Sea Temperatures in Key West, °F
Sea water temperature in August, °F
Show year:
2026
2025
2024
The average sea water temperature in August of 2026 was 88.8°F. The highest and lowest sea temperatures during the month were 90.5°F and 87.1°F.
Sea water temperature in July, °F
Show year:
2026
2025
2024
The average sea water temperature in July of 2026 was 88.5°F. The highest and lowest sea temperatures during the month were 90.0°F and 87.4°F.
Sea water temperature in September, °F
Show year:
2025
2024
2023
The average sea water temperature in September of 2025 was 86.9°F. The highest and lowest sea temperatures during the month were 89.2°F and 85.3°F.
current
weather
weather
| Key West |
weather in
September
September
| Key West |
Best time for vacation in Key West
Key West on a weather map
Places in USA:
Name
°F
24 Hours Forecast
Key West
Local time: 16:40
September 14, monday
1800
86°F
SW
4 mph
4 mph
2100
86°F
SW
6 mph
6 mph
September 15, tuesday
0000
86°F
W
8 mph
8 mph
0300
84°F
W
11 mph
11 mph
0600
84°F
NW
11 mph
11 mph
0900
84°F
W
11 mph
11 mph
1200
84°F
W
9 mph
9 mph
1500
86°F
W
8 mph
8 mph
