American Falls Weather in September

What's the weather like in American Falls (Idaho) in September 2025?

The climate in American Falls during September can be summarized as mild and dry.

September is in the fall / autumn in American Falls and is typically the 4th warmest month of the year. Daytime maximum temperatures average around 24°C (75°F), whilst at night 4°C (40°F) is normal.

American Falls weather averages (imperial / metric)
Daytime temperature 23.6°C 74.5°F
Nightly temperature 4.2°C 39.6°F
Average temperature 13.9°C 57°F
Daily sunshine 10.6 hrs
Avg rainfall 17 mm 0.7 ins
Rainy days 5 days
Sea temperature 15.5°C 60°F
Humidity 47%
Windspeed 15.1kph 9 mph

On average September is the 3rd driest month of the year in American Falls with around 17mm 0.7 inches of rain making it a dry time to visit. This rainfall is typically spread over 5 days, although this may vary considerably.

On the flip side this corresponds to an average of 10.6 hours of sunshine per day.

September temperatures in American Falls

American Falls average temperature in September

September rainfall

American Falls average rain in September

September hourly sunshine

American Falls 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 American Falls 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

American Falls weather stats

American Falls weather statistics
Hottest month: July 29.8°C 85.6°F
Driest month: July 14mm 0.6ins
Sunniest month: July 13.3hrs
Coldest month: January -0.3°C 31.5°F
Wettest month: May 32mm 1.3ins
Map showing location of American Falls (42.78602, -112.85444) American Falls map pin © Google

Locations nearby

Top United States locations