Colorado weather in September 2025

Expect 25°C daytime maximum temperatures in the shade with on average 9 hours of sunshine per day in Colorado in September. Check more long-term weather averages for Colorado in September before you book your next holiday to Colorado in 2025/2026.

  • 25°C maximum daytime temperature in September in Colorado (Denver)25
    25°C max day temperature
  • 9 hours of sunshine per day
  • 7 days with some rainfall in September in Colorado (Denver)7
    7 days with some rainfall
  • 8°C minimum night-time temperature in September in Colorado (Denver)8
    8°C min night temperature
  • 12 hours of daylight per day in September in Colorado (Denver)12
    12 hours of daylight per day
  • No heat & humidity in September in Colorado (Denver)0
    No heat & humidity
  • 30 mm monthly rainfall in September in Colorado (Denver)30
    30 mm of monthly rainfall
  • UV (maximum) index 7 (High) in September in Colorado (Denver)7
    7 (High) UV index

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The September weather guide for Colorado (Denver) 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.

Top Colorado destinations

Below are average maximum temperatures at popular countries, regions and places in Colorado in September. Select a holiday destination to see more weather parameters.

All Colorado destinations

Metric (°C / mm)  |  Imperial (°F / inches)

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How hot is it in Colorado in September?

Daytime temperatures usually reach 25°C in Denver, Colorado in September with no heat and humidity, falling to 8°C at night.

How sunny is it in Colorado in September?

There are normally 9 hours of bright sunshine each day in Denver, Colorado in September - that's 73% of daylight hours.

Does it rain in Colorado in September?

There are usually 7 days with some rain in Denver, Colorado in September and the average monthly rainfall is 30mm.

Colorado September sunrise & sunset times

Browse the sunrise and sunset times for Colorado in September 2025. Select a month to view Colorado sunrise and sunset times for the next 12 months. The Colorado sunrise and sunset times shown below are for Denver.

JanFebMarAprMayJunJulAugSepOctNovDec

Date Sunrise times Sunset times
Monday, 1st September 2025 05:28 18:31
Monday, 15th September 2025 05:41 18:08
Tuesday, 30th September 2025 05:56 17:43

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