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September Weather in Cheyenne, United States

Last updated: June 24, 2025

In Cheyenne, United States, the average temperature in September hovers around 23°C (74°F), making it a pleasant time to explore. Expect minimums of 6°C (42°F) and maximums reaching up to 37°C (99°F), so be prepared for a range of weather. With 55 mm (2.2 in) of precipitation over 6 days, a little rain might be on the horizon, while average humidity sits at 64%, adding to the warm feel of the month.

September Temperature in Cheyenne

In September in Cheyenne, the average temperature is 23°C (74°F). Maximums can reach 37°C (99°F), and minimums can be as low as 6°C (42°F). Be sure to pack accordingly to enjoy a comfortable trip!

September Weather in Cheyenne: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Cheyenne, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Cheyenne, September typically has an average temperature of 23°C (74°F), with highs reaching up to 37°C (99°F) and lows dropping to around 6°C (42°F).
JanFebMarAprMayJunJulAugSepOctNovDec373851586877818073594842
Data source: Temperature data for Cheyenne generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Cheyenne

In Cheyenne in September, the total precipitation amount is 55 mm (2.2 in) spread over 6 days.

September Precipitation Trends in Cheyenne

The chart displays monthly precipitation patterns in Cheyenne, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Cheyenne, September typically receives around 55 mm (2.2 inches) of precipitation spread over approximately 6 days.
JanFebMarAprMayJunJulAugSepOctNovDec2618795610573494555731321
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Cheyenne

In Cheyenne in September, humidity is 64%. With an average temperature of 23°C (74°F), this humidity feels like a warm blanket wrapping around you, making outdoor exploration enjoyable yet slightly sticky, so it's best to stay hydrated and take breaks in the shade while traveling.

September Average Humidity in Cheyenne

This chart illustrates the average monthly humidity levels in Cheyenne, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Cheyenne is approximately 64%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec76%76%70%72%82%82%80%72%64%71%81%84%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Cheyenne

In Cheyenne in September, the maximum UV index reaches 10, which corresponds to a very high Exposure Category. With a time to burn of just 15 minutes, it's crucial to take precautions. For more detailed information, you can check the Hourly UV Index in Cheyenne.

Maximum UV Index Levels in Cheyenne for September

The chart shows the monthly maximum UV Index (UVI) for Cheyenne in September, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In September, the maximum UV index in Cheyenne typically reaches 10, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec468101111121110754
Data source: Cheyenne September UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

  •  Extreme (11+): Avoid the sun, stay in shade.
  •  Very High (8-10): Limit sun exposure.
  •  High (6-7): Use SPF 30+ and protective clothing.
  •  Moderate (3-5): Midday shade recommended.
  •  Low (0-2): No protection needed.

How September Weather in Cheyenne Compares to Other Months

Weather in Cheyenne varies notably across the year, with each month offering distinct climate conditions. This page compares September’s weather to other months in Cheyenne, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Cheyenne, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather3°C (38°F)26 mm (1.0 inches)76%moderate
February Weather4°C (39°F)18 mm (0.7 inches)76%high
March Weather11°C (51°F)79 mm (3.1 inches)70%very high
April Weather14°C (58°F)56 mm (2.2 inches)72%very high
May Weather20°C (68°F)105 mm (4.2 inches)82%extreme
June Weather25°C (78°F)73 mm (2.9 inches)82%extreme
July Weather27°C (81°F)49 mm (1.9 inches)80%extreme
August Weather26°C (80°F)45 mm (1.8 inches)72%extreme
September Weather23°C (74°F)55 mm (2.2 inches)64%very high
October Weather15°C (59°F)73 mm (2.9 inches)71%high
November Weather9°C (48°F)13 mm (0.5 inches)81%moderate
December Weather5°C (42°F)21 mm (0.8 inches)84%moderate

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