Hilton Head Island Weather in September

The climate in Hilton Head Island during September can be summarized as hot, humid and wet.

September is in the fall / autumn in Hilton Head Island and is typically the 4th warmest month of the year. Daytime maximum temperatures average around a muggy 29°C (84°F), whilst at night 21°C (69°F) is normal.

On average September is the 4th wettest month of the year in Hilton Head Island with around 134mm 5.3 inches of rain making it a wet time to visit. This rainfall is typically spread over 10 days, although this may vary considerably.

On the flip side this corresponds to an average of 7.7 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 Hilton Head Island in September 2025.