Grand Forks Weather in September

What's the weather like in Grand Forks (North Dakota) in September 2025?

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

September is in the fall / autumn in Grand Forks and is typically the 4th warmest month of the year. Daytime maximum temperatures average around 21°C (70°F), whilst at night 7°C (45°F) is normal.

Grand Forks weather averages (imperial / metric)
Daytime temperature 20.9°C 69.5°F
Nightly temperature 7.2°C 44.9°F
Average temperature 14°C 57.2°F
Daily sunshine 7.5 hrs
Avg rainfall 55 mm 2.2 ins
Rainy days 8 days
Sea temperature 14.5°C 58.1°F
Humidity 70%
Windspeed 17.6kph 11 mph

On average September is the 4th wettest month of the year in Grand Forks with around 55mm 2.2 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 7.5 hours of sunshine per day.

September temperatures in Grand Forks

Grand Forks average temperature in September

September rainfall

Grand Forks average rain in September

September hourly sunshine

Grand Forks 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 Grand Forks 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

Grand Forks weather stats

Grand Forks weather statistics
Hottest month: July 27.7°C 81.9°F
Driest month: February 12mm 0.5ins
Sunniest month: July 11.7hrs
Coldest month: January -10.5°C 13.1°F
Wettest month: June 80mm 3.1ins
Map showing location of Grand Forks (47.92526, -97.03285) Grand Forks map pin © Google

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