Sumter Weather in September

What's the weather like in Sumter (South Carolina) in September 2025?

The climate in Sumter during September can be summarized as warm, humid and a little damp.

September is in the fall / autumn in Sumter and is typically the 4th warmest month of the year. Daytime maximum temperatures average around a muggy 29°C (84°F), whilst at night 17°C (62°F) is normal.

Sumter weather averages (imperial / metric)
Daytime temperature 29.1°C 84.4°F
Nightly temperature 16.7°C 62.1°F
Average temperature 22.9°C 73.2°F
Daily sunshine 8.3 hrs
Avg rainfall 91 mm 3.6 ins
Rainy days 8 days
Sea temperature 27.3°C 81.1°F
Humidity 76%
Windspeed 11.5kph 7 mph

On average September is the 6th driest month of the year in Sumter with around 91mm 3.6 inches of rain making it a a little 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 8.3 hours of sunshine per day.

September temperatures in Sumter

Sumter average temperature in September

September rainfall

Sumter average rain in September

September hourly sunshine

Sumter average rain in September

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 Sumter in September 2025.

Other monthly averages

Best places to visit in September

UV index Best time to go?

Beta

Current (hourly) weather 15 day forecast

Sumter weather stats

Sumter weather statistics
Hottest month: July 32.2°C 90°F
Driest month: November 63mm 2.5ins
Sunniest month: April 9.6hrs
Coldest month: January 12.4°C 54.3°F
Wettest month: July 142mm 5.6ins
Map showing location of Sumter (33.92044, -80.34147) Sumter map pin © Google

Locations nearby

Top United States locations