September Weather in Wyoming, United States

Last updated: June 24, 2025

In September, the average temperature in Wyoming, United States is a pleasant 18°C (64°F). However, temperatures can vary significantly, with a minimum of 1°C (35°F) and a maximum reaching 32°C (91°F). Rainfall is also a factor to consider, with an average precipitation of 111 mm (4.4 in) spread over about 10 days. Coupled with an average humidity of 81%, it's clear that Wyoming offers a unique climate experience this month!

September Temperature in Wyoming

In September in Wyoming, the average temperature is 18°C (64°F). Maximum temperatures can reach 32°C (91°F), while minimums can drop as low as 1°C (35°F). Overall, it's a great time to visit Wyoming, as you can experience a pleasant mix of warm and cooler days perfect for exploring.

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 18°C (64°F), with highs reaching up to 32°C (91°F) and lows dropping to around 1°C (35°F).

Data source: Temperature data for Wyoming generated using information from the Copernicus Climate Change Service.

September Precipitation in Wyoming

In Wyoming in September, the precipitation amount is 111 mm (4.4 in) over a span of 10 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 111 mm (4.4 inches) of precipitation spread over approximately 10 days.

Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

September Humidity in Wyoming

In Wyoming in September, humidity is 81%. With an average temperature of 18°C (64°F), this humidity feels like a warm embrace, making travel both refreshing and slightly stifling at the same time.

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 81%, offering insight into how humid the weather typically is during this month.

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 7, which corresponds to the high Exposure Category. This means that the time to burn is approximately 25 minutes. For more detailed information, you can check 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 7, which falls under the high exposure category.

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.
	Temperature	Precipitation	Humidity	UV
January Weather	-9°C (16°F)	24 mm (0.9 inches)	87%	low
February Weather	-9°C (17°F)	34 mm (1.3 inches)	90%	moderate
March Weather	0°C (33°F)	53 mm (2.1 inches)	85%	moderate
April Weather	6°C (43°F)	90 mm (3.5 inches)	84%	high
May Weather	15°C (59°F)	122 mm (4.8 inches)	78%	very high
June Weather	22°C (71°F)	85 mm (3.3 inches)	80%	very high
July Weather	23°C (74°F)	105 mm (4.1 inches)	81%	very high
August Weather	21°C (71°F)	128 mm (5.1 inches)	81%	very high
September Weather	18°C (64°F)	111 mm (4.4 inches)	81%	high
October Weather	9°C (48°F)	104 mm (4.1 inches)	84%	moderate
November Weather	0°C (33°F)	37 mm (1.4 inches)	88%	moderate
December Weather	-5°C (23°F)	52 mm (2.0 inches)	84%	low