Idaho City Weather in September

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

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

September is in the fall / autumn in Idaho City and is typically the 4th warmest month of the year. Daytime maximum temperatures average around 23°C (73°F), whilst at night 4°C (39°F) is normal.

Idaho City weather averages (imperial / metric)
Daytime temperature 22.6°C 72.7°F
Nightly temperature 3.8°C 38.8°F
Average temperature 13.2°C 55.8°F
Daily sunshine 10.6 hrs
Avg rainfall 30 mm 1.2 ins
Rainy days 5 days
Sea temperature 14.7°C 58.4°F
Humidity 47%
Windspeed 14kph 9 mph

On average September is the 3rd driest month of the year in Idaho City with around 30mm 1.2 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 Idaho City

Idaho City average temperature in September

September rainfall

Idaho City average rain in September

September hourly sunshine

Idaho City 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 Idaho City 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

Idaho City weather stats

Idaho City weather statistics
Hottest month: July 28.5°C 83.3°F
Driest month: July 13mm 0.5ins
Sunniest month: July 13.6hrs
Coldest month: January -1°C 30.2°F
Wettest month: January 93mm 3.7ins
Map showing location of Idaho City (43.8285, -115.83455) Idaho City map pin © Google

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