September Weather in Billings, United States

Last updated: June 24, 2025

In September, the average temperature in Billings, United States is a pleasant 17°C (62°F), but it can swing from a cool 2°C (36°F) to a scorching 38°C (101°F). The region sees about 42 mm (1.7 in) of precipitation over 5 days, contributing to an average humidity of 76%. Be sure to pack accordingly!

September Temperature in Billings

In September in Billings, the average temperature is 17°C (62°F). Maximum temperatures can reach 38°C (101°F), while minimums can drop to as low as 2°C (36°F). Travelers should be prepared for a wide range of temperatures and pack accordingly.

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

The chart illustrates September temperature patterns in Billings, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Billings, September typically has an average temperature of 17°C (62°F), with highs reaching up to 38°C (101°F) and lows dropping to around 2°C (36°F).

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

September Precipitation in Billings

In Billings in September, the precipitation amount is 42 mm (1.7 in) over a span of 5 days.

September Precipitation Trends in Billings

The chart displays monthly precipitation patterns in Billings, 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 Billings, September typically receives around 42 mm (1.7 inches) of precipitation spread over approximately 5 days.

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

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

September Humidity in Billings

In Billings in September, humidity is 76%. With an average temperature of 17°C (62°F), this humidity feels like a warm, enveloping embrace, making travel feel slightly more challenging as it can lead to a sticky discomfort, especially during outdoor excursions.

September Average Humidity in Billings

This chart illustrates the average monthly humidity levels in Billings, 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 Billings is approximately 76%, 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 Billings

In Billings 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 Billings.

Maximum UV Index Levels in Billings for September

The chart shows the monthly maximum UV Index (UVI) for Billings 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 Billings typically reaches 8, which falls under the very high exposure category.

Data source: Billings 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 Billings Compares to Other Months

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

This table compares monthly weather conditions in Billings, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-3°C (27°F)	19 mm (0.7 inches)	85%	moderate
February Weather	-6°C (21°F)	43 mm (1.7 inches)	85%	moderate
March Weather	3°C (37°F)	33 mm (1.3 inches)	79%	high
April Weather	7°C (44°F)	66 mm (2.6 inches)	74%	very high
May Weather	13°C (55°F)	63 mm (2.5 inches)	76%	very high
June Weather	19°C (67°F)	53 mm (2.1 inches)	79%	extreme
July Weather	24°C (75°F)	18 mm (0.7 inches)	81%	very high
August Weather	22°C (73°F)	16 mm (0.6 inches)	80%	very high
September Weather	17°C (62°F)	42 mm (1.7 inches)	76%	very high
October Weather	8°C (46°F)	43 mm (1.7 inches)	74%	moderate
November Weather	3°C (37°F)	28 mm (1.1 inches)	81%	moderate
December Weather	-1°C (30°F)	29 mm (1.1 inches)	87%	low