September Weather in Basin, United States

Last updated: June 24, 2025

In September, the average temperature in Basin, United States hovers around 17°C (63°F), with minimums dipping to 1°C (34°F) and maximums soaring to 35°C (96°F). Expect about 30 mm (1.2 in) of precipitation over 4 days, contributing to an average humidity of 76%. Stay prepared for a mix of weather as you explore this vibrant locale!

September Temperature in Basin

In September in Basin, the average temperature is 17°C (63°F). The maximum can reach 35°C (96°F) and the minimum can be as low as 1°C (34°F). This variety in temperatures makes it essential for travelers to pack both light clothing for warm days and warmer layers for cooler evenings.

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

The chart illustrates September temperature patterns in Basin, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Basin, September typically has an average temperature of 17°C (63°F), with highs reaching up to 35°C (96°F) and lows dropping to around 1°C (34°F).

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

September Precipitation in Basin

In Basin in September, the precipitation amount is 30 mm (1.2 in) over the course of 4 days.

September Precipitation Trends in Basin

The chart displays monthly precipitation patterns in Basin, 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 Basin, September typically receives around 30 mm (1.2 inches) of precipitation spread over approximately 4 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 Basin

In Basin in September humidity is 76%. With an average temperature of 17°C (63°F), this humidity feels like traveling through a warm, enveloping blanket, making every outdoor adventure feel sticky and heavy, yet pleasantly refreshing when you find a cool breeze.

September Average Humidity in Basin

This chart illustrates the average monthly humidity levels in Basin, 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 Basin 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 Basin

In Basin in September, the maximum UV index is 9, which corresponds to a very high Exposure Category. The time to burn is just 15 minutes, so it's essential to take precautions. For detailed information, you can check the Hourly UV Index in Basin.

Maximum UV Index Levels in Basin for September

The chart shows the monthly maximum UV Index (UVI) for Basin 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 Basin typically reaches 9, which falls under the very high exposure category.

Data source: Basin 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 Basin Compares to Other Months

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

This table compares monthly weather conditions in Basin, 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)	10 mm (0.4 inches)	85%	moderate
February Weather	-5°C (24°F)	21 mm (0.8 inches)	85%	moderate
March Weather	5°C (40°F)	14 mm (0.5 inches)	79%	high
April Weather	8°C (46°F)	30 mm (1.2 inches)	74%	very high
May Weather	13°C (56°F)	37 mm (1.5 inches)	76%	very high
June Weather	20°C (69°F)	14 mm (0.5 inches)	79%	extreme
July Weather	25°C (77°F)	7 mm (0.3 inches)	81%	extreme
August Weather	23°C (73°F)	11 mm (0.4 inches)	80%	very high
September Weather	17°C (63°F)	30 mm (1.2 inches)	76%	very high
October Weather	7°C (45°F)	29 mm (1.1 inches)	74%	high
November Weather	2°C (37°F)	12 mm (0.5 inches)	81%	moderate
December Weather	-2°C (29°F)	14 mm (0.5 inches)	87%	low