Challis Weather in September

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

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

September is in the fall / autumn in Challis and is typically the 4th warmest month of the year. Daytime maximum temperatures average around a cool 22°C (71°F), whilst at night 3°C (38°F) is normal.

Challis weather averages (imperial / metric)
Daytime temperature 21.5°C 70.7°F
Nightly temperature 3.1°C 37.6°F
Average temperature 12.3°C 54.1°F
Daily sunshine 9.8 hrs
Avg rainfall 21 mm 0.8 ins
Rainy days 7 days
Sea temperature 14.4°C 57.9°F
Humidity 52%
Windspeed 13.7kph 9 mph

On average September is the 6th wettest month of the year in Challis with around 21mm 0.8 inches of rain making it a 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 9.8 hours of sunshine per day.

September temperatures in Challis

Challis average temperature in September

September rainfall

Challis average rain in September

September hourly sunshine

Challis 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 Challis 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

Challis weather stats

Challis weather statistics
Hottest month: July 27.9°C 82.2°F
Driest month: October 17mm 0.7ins
Sunniest month: July 12.9hrs
Coldest month: January -1.8°C 28.8°F
Wettest month: June 35mm 1.4ins
Map showing location of Challis (44.50464, -114.23173) Challis map pin © Google

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