Bison Weather in September

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

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

September is in the fall / autumn in Bison and is typically the 4th warmest month of the year. Daytime maximum temperatures average around 23°C (73°F), whilst at night 7°C (44°F) is normal.

Bison weather averages (imperial / metric)
Daytime temperature 22.7°C 72.8°F
Nightly temperature 6.6°C 43.8°F
Average temperature 14.6°C 58.3°F
Daily sunshine 9.3 hrs
Avg rainfall 33 mm 1.3 ins
Rainy days 7 days
Sea temperature 15.2°C 59.4°F
Humidity 58%
Windspeed 17.3kph 11 mph

On average September is the 6th wettest month of the year in Bison with around 33mm 1.3 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 9.3 hours of sunshine per day.

September temperatures in Bison

Bison average temperature in September

September rainfall

Bison average rain in September

September hourly sunshine

Bison 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 Bison 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

Bison weather stats

Bison weather statistics
Hottest month: July 29.8°C 85.6°F
Driest month: January 7mm 0.3ins
Sunniest month: August 11.3hrs
Coldest month: January -3.1°C 26.4°F
Wettest month: June 82mm 3.2ins
Map showing location of Bison (45.52026, -102.46127) Bison map pin © Google

Locations nearby

Top United States locations