De Smet Weather in September

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

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

September is in the fall / autumn in De Smet and is typically the 4th warmest month of the year. Daytime maximum temperatures average around 23°C (73°F), whilst at night 8°C (47°F) is normal.

De Smet weather averages (imperial / metric)
Daytime temperature 22.5°C 72.5°F
Nightly temperature 8.1°C 46.6°F
Average temperature 15.3°C 59.5°F
Daily sunshine 9 hrs
Avg rainfall 54 mm 2.1 ins
Rainy days 8 days
Sea temperature 16.4°C 61.6°F
Humidity 69%
Windspeed 18.4kph 11 mph

On average September is the 6th wettest month of the year in De Smet with around 54mm 2.1 inches of rain making it a reasonably dry 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 hours of sunshine per day.

September temperatures in De Smet

De Smet average temperature in September

September rainfall

De Smet average rain in September

September hourly sunshine

De Smet 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 De Smet 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

De Smet weather stats

De Smet weather statistics
Hottest month: July 29.4°C 84.9°F
Driest month: January 13mm 0.5ins
Sunniest month: July 12.3hrs
Coldest month: January -6°C 21.2°F
Wettest month: June 103mm 4.1ins
Map showing location of De Smet (44.38747, -97.55035) De Smet map pin © Google

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