Lewiston weather in September 2025

Expect 77°F daytime maximum temperatures in the shade with on average 9 hours of sunshine per day in Lewiston in September. Check more long-term weather averages for Lewiston in September before you book your next holiday to Idaho in 2025/2026.

  • 77°F maximum daytime temperature in September in Lewiston77
    77°F max day temperature
  • 9 hours of sunshine per day
  • 6 days with some rainfall in September in Lewiston6
    6 days with some rainfall
  • 48°F minimum night-time temperature in September in Lewiston48
    48°F min night temperature
  • 12 hours of daylight per day in September in Lewiston12
    12 hours of daylight per day
  • No heat & humidity in September in Lewiston0
    No heat & humidity
  • 0.8 inches monthly rainfall in September in Lewiston0.8
    0.8 inches of monthly rainfall
  • UV (maximum) index 5 (Moderate) in September in Lewiston5
    5 (Moderate) UV index

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The September weather guide for Idaho (Lewiston) shows long term weather averages processed from data supplied by CRU (University of East Anglia), the Met Office & the Netherlands Meteorological Institute. Find out more about our data sources.

Metric (°C)  |  Imperial (°F)

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How hot is it in Lewiston in September?

Daytime temperatures usually reach 77°F in Lewiston in September with no heat and humidity, falling to 48°F at night.

How sunny is it in Lewiston in September?

There are normally 9 hours of bright sunshine each day in Lewiston in September - that's 74% of daylight hours.

Does it rain in Lewiston in September?

There are usually 6 days with some rain in Lewiston in September and the average monthly rainfall is 0.8 inches.

Lewiston September sunrise & sunset times

Browse the sunrise and sunset times for Lewiston in September 2025. Select a month to view Lewiston sunrise and sunset times for the next 12 months.

JanFebMarAprMayJunJulAugSepOctNovDec

Date Sunrise times Sunset times
Monday, 1st September 2025 05:09 18:26
Monday, 15th September 2025 05:27 17:59
Tuesday, 30th September 2025 05:46 17:29

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