nomadseason

September Weather in Wyoming, United States

Last updated: June 24, 2025

In September, the average temperature in Wyoming, United States is a pleasant 21°C (69°F). Expect temperatures to range from a cool 5°C (42°F) to a warm 34°C (94°F). During this month, you'll encounter approximately 88 mm (3.5 in) of precipitation spread over 8 days, giving the air an average humidity of around 80%. Embrace the mix of warm days and refreshing showers!

September Temperature in Wyoming

In September in Wyoming, the average temperature is 21°C (69°F), with maximums reaching 34°C (94°F) and minimums as low as 5°C (42°F). This varied climate makes it an ideal destination for travelers seeking both warm and cool experiences.

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

The chart illustrates September temperature patterns in Wyoming, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Wyoming, September typically has an average temperature of 21°C (69°F), with highs reaching up to 34°C (94°F) and lows dropping to around 5°C (42°F).
JanFebMarAprMayJunJulAugSepOctNovDec252841506373777469553933
Data source: Temperature data for Wyoming generated using information from the Copernicus Climate Change Service.
Choose your preferred temperature unit
The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Wyoming

In Wyoming in September, the precipitation amount is 88 mm (3.5 in) over the course of 8 days.

September Precipitation Trends in Wyoming

The chart displays monthly precipitation patterns in Wyoming, 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 Wyoming, September typically receives around 88 mm (3.5 inches) of precipitation spread over approximately 8 days.
JanFebMarAprMayJunJulAugSepOctNovDec586510411516215910368881335551
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

September Humidity in Wyoming

In Wyoming in September, humidity is 80%. With an average temperature of 21°C (69°F), this humidity feels like a warm, sticky embrace, making outdoor activities a bit challenging for travelers as the air becomes heavy and can lead to fatigue while sightseeing.

September Average Humidity in Wyoming

This chart illustrates the average monthly humidity levels in Wyoming, 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 Wyoming is approximately 80%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec82%83%84%85%79%82%80%81%80%82%88%84%
Data source: Humidity data for September generated using information from the Copernicus Climate Change Service.

September UV Index in Wyoming

In Wyoming in September, the maximum UV index is 8, which corresponds to a very high Exposure Category. This means that the time to burn is only 15 minutes. For more detailed information, you can refer to the Hourly UV Index in Wyoming.

Maximum UV Index Levels in Wyoming for September

The chart shows the monthly maximum UV Index (UVI) for Wyoming 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 Wyoming typically reaches 8, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec35689111098642
Data source: Wyoming 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 Wyoming Compares to Other Months

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

This table compares monthly weather conditions in Wyoming, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-4°C (26°F)58 mm (2.3 inches)82%moderate
February Weather-2°C (28°F)65 mm (2.6 inches)83%moderate
March Weather5°C (41°F)104 mm (4.1 inches)84%high
April Weather10°C (50°F)115 mm (4.5 inches)85%very high
May Weather17°C (63°F)162 mm (6.4 inches)79%very high
June Weather23°C (74°F)159 mm (6.3 inches)82%extreme
July Weather25°C (77°F)103 mm (4.1 inches)80%very high
August Weather23°C (74°F)68 mm (2.7 inches)81%very high
September Weather21°C (69°F)88 mm (3.5 inches)80%very high
October Weather13°C (55°F)133 mm (5.2 inches)82%high
November Weather4°C (40°F)55 mm (2.2 inches)88%moderate
December Weather1°C (34°F)51 mm (2.0 inches)84%low

Compare Wyoming's Climate with Cities Worldwide