Lewistown weather in September 2025

Expect 20°C daytime maximum temperatures in the shade with on average 9 hours of sunshine per day in Lewistown in September. Check more long-term weather averages for Lewistown in September before you book your next holiday to Montana in 2025/2026.

  • 20°C maximum daytime temperature in September in Lewistown20
    20°C max day temperature
  • 9 hours of sunshine per day
  • 7 days with some rainfall in September in Lewistown7
    7 days with some rainfall
  • 5°C minimum night-time temperature in September in Lewistown5
    5°C min night temperature
  • 13 hours of daylight per day in September in Lewistown13
    13 hours of daylight per day
  • No heat & humidity in September in Lewistown0
    No heat & humidity
  • 37 mm monthly rainfall in September in Lewistown37
    37 mm of monthly rainfall
  • UV (maximum) index 5 (Moderate) in September in Lewistown5
    5 (Moderate) UV index

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The September weather guide for Montana (Lewistown) 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 / mm)  |  Imperial (°F / inches)

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How hot is it in Lewistown in September?

Daytime temperatures usually reach 20°C in Lewistown in September, falling to 5°C at night.

How sunny is it in Lewistown in September?

There are normally 9 hours of bright sunshine each day in Lewistown in September - that's 68% of daylight hours.

Does it rain in Lewistown in September?

There are usually 7 days with some rain in Lewistown in September and the average monthly rainfall is 37mm.

Lewistown September sunrise & sunset times

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

JanFebMarAprMayJunJulAugSepOctNovDec

Date Sunrise times Sunset times
Monday, 1st September 2025 05:38 18:57
Monday, 15th September 2025 05:56 18:29
Tuesday, 30th September 2025 06:16 17:59

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