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Casper weather in September 2025
Expect 23°C daytime maximum temperatures in the shade with on average 9 hours of sunshine per day in Casper in September. Check more long-term weather averages for Casper in September before you book your next holiday to Wyoming in 2025/2026.
- 2323°C max day temperature
- 9 hours of sunshine per day
- 77 days with some rainfall
- 55°C min night temperature
- 1212 hours of daylight per day
- 0No heat & humidity
- 2424 mm of monthly rainfall
- 77 (High) UV index
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The September weather guide for Wyoming (Casper) 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)
More about the USA
How hot is it in Casper in September?
Daytime temperatures usually reach 23°C in Casper in September, falling to 5°C at night.
How sunny is it in Casper in September?
There are normally 9 hours of bright sunshine each day in Casper in September - that's 70% of daylight hours.
Does it rain in Casper in September?
There are usually 7 days with some rain in Casper in September and the average monthly rainfall is 24mm.
Casper September sunrise & sunset times
Browse the sunrise and sunset times for Casper in September 2025. Select a month to view Casper sunrise and sunset times for the next 12 months.
JanFebMarAprMayJunJulAugSepOctNovDec
Date | Sunrise times | Sunset times |
---|---|---|
Monday, 1st September 2025 | 05:30 | 18:39 |
Monday, 15th September 2025 | 05:45 | 18:14 |
Tuesday, 30th September 2025 | 06:02 | 17:48 |
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