Twin Falls Weather in September

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

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

September is in the fall / autumn in Twin Falls and is typically the 4th warmest month of the year. Daytime maximum temperatures average around 25°C (77°F), whilst at night 7°C (45°F) is normal.

Twin Falls weather averages (imperial / metric)
Daytime temperature 24.9°C 76.7°F
Nightly temperature 7°C 44.5°F
Average temperature 15.9°C 60.6°F
Daily sunshine 10.8 hrs
Avg rainfall 15 mm 0.6 ins
Rainy days 5 days
Sea temperature 15.2°C 59.4°F
Humidity 45%
Windspeed 14.8kph 9 mph

On average September is the 3rd driest month of the year in Twin Falls with around 15mm 0.6 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 10.8 hours of sunshine per day.

September temperatures in Twin Falls

Twin Falls average temperature in September

September rainfall

Twin Falls average rain in September

September hourly sunshine

Twin 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 Twin 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

Twin Falls weather stats

Twin Falls weather statistics
Hottest month: July 31.6°C 88.9°F
Driest month: July 8mm 0.3ins
Sunniest month: July 13.6hrs
Coldest month: January 1.7°C 35.1°F
Wettest month: January 30mm 1.2ins
Map showing location of Twin Falls (42.56297, -114.46087) Twin Falls map pin © Google

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