September Weather in Butte, United States

Last updated: June 24, 2025

In Butte, United States, the average temperature in September hovers around 19°C (67°F). Expect minimums dipping to 3°C (38°F) and soaring highs of 35°C (95°F). With an average precipitation of 68 mm (2.7 in) spread over 6 days, and humidity levels reaching 75%, be prepared for a mix of warmth and occasional rain!

September Temperature in Butte

In September in Butte, the average temperature is 19°C (67°F). Maximums can reach 35°C (95°F), while minimums can dip as low as 3°C (38°F). This variability makes Butte a great destination for travelers seeking a mix of warm and cooler weather experiences.

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

The chart illustrates September temperature patterns in Butte, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Butte, September typically has an average temperature of 19°C (67°F), with highs reaching up to 35°C (95°F) and lows dropping to around 3°C (38°F).

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

September Precipitation in Butte

In Butte in September, the precipitation amount is 68 mm (2.7 in) spread over the course of 6 days.

September Precipitation Trends in Butte

The chart displays monthly precipitation patterns in Butte, 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 Butte, September typically receives around 68 mm (2.7 inches) of precipitation spread over approximately 6 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 Butte

In Butte in September humidity is 75%. With an average temperature of 19°C (67°F), this humidity feels like a warm embrace, making travel invigorating yet slightly sticky, as you navigate through the vibrant streets or scenic landscapes.

September Average Humidity in Butte

This chart illustrates the average monthly humidity levels in Butte, 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 Butte is approximately 75%, 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 Butte

In Butte 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 Butte.

Maximum UV Index Levels in Butte for September

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

Data source: Butte 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 Butte Compares to Other Months

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

This table compares monthly weather conditions in Butte, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-5°C (23°F)	21 mm (0.8 inches)	77%	moderate
February Weather	-6°C (22°F)	22 mm (0.9 inches)	81%	moderate
March Weather	3°C (37°F)	69 mm (2.7 inches)	71%	high
April Weather	7°C (46°F)	58 mm (2.3 inches)	75%	very high
May Weather	15°C (59°F)	127 mm (5.0 inches)	74%	very high
June Weather	23°C (74°F)	69 mm (2.7 inches)	82%	extreme
July Weather	25°C (77°F)	81 mm (3.2 inches)	84%	very high
August Weather	23°C (74°F)	80 mm (3.2 inches)	82%	very high
September Weather	19°C (67°F)	68 mm (2.7 inches)	75%	very high
October Weather	9°C (49°F)	72 mm (2.8 inches)	72%	moderate
November Weather	3°C (38°F)	21 mm (0.8 inches)	81%	moderate
December Weather	-2°C (28°F)	42 mm (1.6 inches)	79%	low