World Resorts USA Key West Weather

Key West Sea Temperature in September

Average sea water temperature in September:
+86.2°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:
2026
2025
2024

The average sea water temperature in September of 2026 was 87.8°F. The highest and lowest sea temperatures during the month were 89.4°F and 85.8°F.

Monthly sea water temperature in Key West, °F

Which USA resorts have warmest sea in September?

Place name September 2026 September 2025
Key West 87.8°F 86.9°F
Naples 87.0°F 86.1°F
Galveston 87.0°F 85.5°F
Siesta Key 86.9°F 84.9°F
Houston 86.9°F 84.9°F
Corpus Christi 86.8°F 85.8°F
Sarasota 86.8°F 84.8°F
West Palm Beach 86.6°F 86.2°F
Fort Lauderdale 86.6°F 86.4°F
New Orleans 86.4°F 84.3°F
Gulf Shores 86.1°F 84.3°F
St. Petersburg 86.1°F 84.1°F
Orange Beach 86.0°F 84.0°F
Pensacola Beach 85.9°F 83.9°F
Tampa 85.9°F 84.3°F
Clearwater Beach 85.9°F 84.0°F
Miami Beach 85.8°F 86.1°F
Panama City Beach 85.8°F 83.4°F
Pensacola 85.7°F 83.9°F
Destin 85.6°F 83.1°F

Best time for vacation in Key West

Sunniest months:
May 17 days
March 16 days
April 16 days
Warmest months:
August 87.4 °F
July 86.9 °F
September 85.6 °F
Warmest sea temp:
August 87.3 °F
July 86.7 °F
September 86.2 °F
Coldest months:
January 72.0 °F
February 73.7 °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
S 19 mph
Feels like: +79°F
Precip.: 7%
Places in USA:
Name
°F
+36°F
+39°F
+70°F
+61°F
+63°F
+66°F
+63°F
+39°F
+63°F
+55°F
+63°F
+64°F
+59°F
+63°F
+37°F
24 Hours Forecast
Key West
Local time: 01:12
November 14, saturday
0300
75°F
S
17 mph
0600
73°F
S
17 mph
0900
72°F
SW
17 mph
1200
70°F
SW
15 mph
1500
70°F
S
16 mph
1800
70°F
S
15 mph
2100
72°F
SW
13 mph
November 15, sunday
0000
72°F
SW
13 mph
Units of measurement: °C / °F