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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 (71°F), with temperatures ranging from a cool 7°C (44°F) to a warm 35°C (95°F). Expect 81 mm (3.2 in) of precipitation over about 8 days, adding to the average humidity of 73% for a truly tropical experience.

September Temperature in Wyoming

In September in Wyoming, the average temperature is 21°C (71°F). Maximum temperatures can reach 35°C (95°F), while minimums can drop as low as 7°C (44°F). This makes Wyoming a great destination for travelers who enjoy a mix of warm days and cooler evenings.

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 (71°F), with highs reaching up to 35°C (95°F) and lows dropping to around 7°C (44°F).
JanFebMarAprMayJunJulAugSepOctNovDec333745546674787571594439
Data source: Temperature data for Wyoming 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 Wyoming

In Wyoming in September, the precipitation amount is 81 mm (3.2 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 81 mm (3.2 inches) of precipitation spread over approximately 8 days.
JanFebMarAprMayJunJulAugSepOctNovDec8010713711912713111089819699110
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Wyoming

In Wyoming in September humidity is 73%. With an average temperature of 21°C (71°F), this humidity feels like a warm, enveloping blanket that can make outdoor activities a bit uncomfortable, but with proper hydration and breaks in the shade, it’s still manageable for traveling.

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 73%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec88%88%87%85%81%82%81%73%73%78%89%87%
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.
JanFebMarAprMayJunJulAugSepOctNovDec356910101098643
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 Weather1°C (33°F)80 mm (3.2 inches)88%moderate
February Weather3°C (37°F)107 mm (4.2 inches)88%moderate
March Weather7°C (45°F)137 mm (5.4 inches)87%high
April Weather12°C (55°F)119 mm (4.7 inches)85%very high
May Weather19°C (66°F)127 mm (5.0 inches)81%very high
June Weather23°C (74°F)131 mm (5.2 inches)82%very high
July Weather25°C (78°F)110 mm (4.3 inches)81%very high
August Weather24°C (75°F)89 mm (3.5 inches)73%very high
September Weather21°C (71°F)81 mm (3.2 inches)73%very high
October Weather15°C (59°F)96 mm (3.8 inches)78%high
November Weather7°C (44°F)99 mm (3.9 inches)89%moderate
December Weather4°C (39°F)110 mm (4.3 inches)87%moderate

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