Average sea water temperature in September:
+86.1°F
| Minimum sea water temperature in September: | 89.6°F |
| Maximum sea water temperature in September: | 82.8°F |
Daily 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.
sea water
temperature
temperature
| Key West |
monthly
weather
weather
| Key West |
current
weather
weather
| Key West |
14 days
forecast
forecast
| Key West |
Monthly sea water temperature in Key West, °F
Which USA resorts have warmest sea in September?
| Place name | September 2025 | September 2024 |
|---|---|---|
| Key West | 86.9°F | 87.4°F |
| Islamorada | 86.7°F | 87.3°F |
| Key Largo | 86.6°F | 87.1°F |
| Fort Lauderdale | 86.4°F | 86.4°F |
| West Palm Beach | 86.2°F | 86.4°F |
| Everglades | 86.2°F | 87.0°F |
| Miami Beach | 86.1°F | 86.3°F |
| Naples | 86.1°F | 87.2°F |
| Marco Island | 86.0°F | 87.2°F |
| South Padre Island | 86.0°F | 85.8°F |
| Corpus Christi | 85.8°F | 84.7°F |
| Miami | 85.8°F | 86.0°F |
| Sanibel Island | 85.7°F | 87.0°F |
| Galveston Island | 85.5°F | 84.4°F |
| Galveston | 85.5°F | 83.7°F |
| Cape Coral | 85.2°F | 86.5°F |
| Houston | 84.9°F | 83.4°F |
| Siesta Key | 84.9°F | 86.8°F |
| Sarasota | 84.8°F | 86.7°F |
| Cocoa Beach | 84.6°F | 85.2°F |
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: 12:40
December 23, tuesday
1500
77°F
W
19 mph
19 mph
1800
77°F
W
21 mph
21 mph
2100
73°F
W
22 mph
22 mph
December 24, wednesday
0000
73°F
W
21 mph
21 mph
0300
73°F
W
17 mph
17 mph
0600
73°F
SW
20 mph
20 mph
0900
72°F
SW
22 mph
22 mph
1200
72°F
SW
18 mph
18 mph
