Riverton weather in September 2026

Expect daytime maximum temperatures of 23°C in Riverton, Wyoming in September based on long-term weather averages. There are 9 hours of sunshine per day on average.

  • 23°C maximum daytime temperature in September in Riverton23
    23°C max day temperature
  • 9 hours of sunshine per day
  • 6 days with some rainfall in September in Riverton6
    6 days with some rainfall
  • 4°C minimum night-time temperature in September in Riverton4
    4°C min night temperature
  • 12 hours of daylight per day in September in Riverton12
    12 hours of daylight per day
  • No heat & humidity in September in Riverton0
    No heat & humidity
  • 20 mm monthly rainfall in September in Riverton20
    20 mm of monthly rainfall
  • UV (maximum) index 6 (High) in September in Riverton6
    6 (High) UV index

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The September weather guide for Wyoming (Riverton) 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 Riverton in September?

Daytime temperatures usually reach 22°C in Riverton in September, falling to 6°C at night.

How sunny is it in Riverton in September?

There are normally 9 hours of bright sunshine each day in Riverton in September - that's 70% of daylight hours.

Does it rain in Riverton in September?

There are usually 7 days with some rain in Riverton in September and the average monthly rainfall is 34mm.

Riverton September sunrise & sunset times

Browse the sunrise and sunset times for Riverton in September 2026. Select a month to view Riverton sunrise and sunset times for the next 12 months.

JanFebMarAprMayJunJulAugSepOctNovDec

Date Sunrise times Sunset times
Tuesday, 1st September 2026 05:38 18:48
Tuesday, 15th September 2026 05:53 18:23
Wednesday, 30th September 2026 06:10 17:56

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