Key West Weather in September

The climate in Key West during September can be summarized as very hot, humid and wet.

September is in the fall / autumn in Key West and is typically the 3rd warmest month of the year. Daytime maximum temperatures average around a steamy 31°C (88°F), whilst at night 25°C (77°F) is normal.

On average September is the wettest month of the year in Key West with around 166mm 6.5 inches of rain making it a wet time to visit. This rainfall is typically spread over 16 days, although this may vary considerably.

On the flip side this corresponds to an average of 9.5 hours of sunshine per day.

The data used in these monthly averages covers a period of over 100 years right up until last year. As such they are a valid prediction of what to expect for the weather in Key West in September 2024.