Nampa Weather in September

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

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

September is in the fall / autumn in Nampa and is typically the 4th warmest month of the year. Daytime maximum temperatures average around a comfortable 26°C (79°F), whilst at night 8°C (46°F) is normal.

Nampa weather averages (imperial / metric)
Daytime temperature 26°C 78.8°F
Nightly temperature 7.6°C 45.7°F
Average temperature 16.8°C 62.2°F
Daily sunshine 10.9 hrs
Avg rainfall 15 mm 0.6 ins
Rainy days 4 days
Sea temperature 14.5°C 58.2°F
Humidity 44%
Windspeed 13.7kph 9 mph

On average September is the 3rd driest month of the year in Nampa with around 15mm 0.6 inches of rain making it a dry time to visit. This rainfall is typically spread over 4 days, although this may vary considerably.

On the flip side this corresponds to an average of 10.9 hours of sunshine per day.

September temperatures in Nampa

Nampa average temperature in September

September rainfall

Nampa average rain in September

September hourly sunshine

Nampa 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 Nampa 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

Nampa weather stats

Nampa weather statistics
Hottest month: July 32.9°C 91.2°F
Driest month: July 6mm 0.2ins
Sunniest month: July 14hrs
Coldest month: January 2.3°C 36.1°F
Wettest month: January 34mm 1.3ins
Map showing location of Nampa (43.54072, -116.56346) Nampa map pin © Google

Locations nearby

Top United States locations