Honolulu Weather in September

The climate in Honolulu during September can be summarized as hot and damp.

September is in the fall / autumn in Honolulu and is typically the 2nd warmest month of the year. Daytime maximum temperatures average around a warm 30°C (86°F), whilst at night 22°C (72°F) is normal.

On average September is the 2nd driest month of the year in Honolulu with around 111mm 4.4 inches of rain making it a damp time to visit. This rainfall is typically spread over 8 days, although this may vary considerably.

On the flip side this corresponds to an average of 9.6 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 Honolulu in September 2025.