Fort Pierre Weather in September

What's the weather like in Fort Pierre (South Dakota) in September 2025?

The climate in Fort Pierre during September can be summarized as mild and reasonably dry.

September is in the fall / autumn in Fort Pierre and is typically the 4th warmest month of the year. Daytime maximum temperatures average around a comfortable 24°C (76°F), whilst at night 9°C (49°F) is normal.

Fort Pierre weather averages (imperial / metric)
Daytime temperature 24.3°C 75.7°F
Nightly temperature 9.3°C 48.7°F
Average temperature 16.8°C 62.2°F
Daily sunshine 9.4 hrs
Avg rainfall 32 mm 1.2 ins
Rainy days 7 days
Sea temperature 16.1°C 60.9°F
Humidity 60%
Windspeed 16.9kph 11 mph

On average September is the 6th wettest month of the year in Fort Pierre with around 32mm 1.2 inches of rain making it a reasonably dry time to visit. This rainfall is typically spread over 7 days, although this may vary considerably.

On the flip side this corresponds to an average of 9.4 hours of sunshine per day.

September temperatures in Fort Pierre

Fort Pierre average temperature in September

September rainfall

Fort Pierre average rain in September

September hourly sunshine

Fort Pierre 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 Fort Pierre 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

Fort Pierre weather stats

Fort Pierre weather statistics
Hottest month: July 31.6°C 88.9°F
Driest month: January 6mm 0.2ins
Sunniest month: July 12.4hrs
Coldest month: January -3.2°C 26.2°F
Wettest month: June 72mm 2.8ins
Map showing location of Fort Pierre (44.35359, -100.37374) Fort Pierre map pin © Google

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