September Weather in Fairmont, United States

Last updated: June 24, 2025

In September, the average temperature in Fairmont, United States typically hovers around 18°C (66°F). Expect daily variations with minimums dropping to 3°C (37°F) and maximums reaching up to 33°C (91°F). Be prepared for some wet days, as 121 mm (4.8 in) of precipitation is likely over approximately 9 days, and the average humidity sits at a comfortable 75%.

September Temperature in Fairmont

In September in Fairmont, the average temperature is 18°C (66°F). Maximum temperatures can soar to 33°C (91°F), while minimums can drop as low as 3°C (37°F). Be sure to pack layers to stay comfortable during your travels!

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

The chart illustrates September temperature patterns in Fairmont, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Fairmont, September typically has an average temperature of 18°C (66°F), with highs reaching up to 33°C (91°F) and lows dropping to around 3°C (37°F).

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

September Precipitation in Fairmont

In Fairmont in September, the precipitation amount is 121 mm (4.8 in) over the course of 9 days.

September Precipitation Trends in Fairmont

The chart displays monthly precipitation patterns in Fairmont, 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 Fairmont, September typically receives around 121 mm (4.8 inches) of precipitation spread over approximately 9 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 Fairmont

In Fairmont in September humidity is 75%. With an average temperature of 18°C (66°F), this humidity feels like traveling through a warm, damp sauna, where the air clings to your skin, making each step feel heavier and more laborious, and creating a unique atmosphere that both enlivens the senses and challenges your comfort level.

September Average Humidity in Fairmont

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

In Fairmont 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 Fairmont.

Maximum UV Index Levels in Fairmont for September

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

Data source: Fairmont 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 Fairmont Compares to Other Months

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

This table compares monthly weather conditions in Fairmont, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-8°C (18°F)	34 mm (1.4 inches)	82%	moderate
February Weather	-8°C (17°F)	38 mm (1.5 inches)	84%	moderate
March Weather	1°C (34°F)	73 mm (2.9 inches)	80%	moderate
April Weather	7°C (45°F)	93 mm (3.7 inches)	81%	very high
May Weather	15°C (60°F)	141 mm (5.6 inches)	74%	very high
June Weather	22°C (73°F)	117 mm (4.6 inches)	80%	very high
July Weather	23°C (75°F)	114 mm (4.5 inches)	80%	very high
August Weather	22°C (71°F)	110 mm (4.3 inches)	77%	very high
September Weather	18°C (66°F)	121 mm (4.8 inches)	75%	very high
October Weather	9°C (49°F)	93 mm (3.7 inches)	80%	moderate
November Weather	2°C (35°F)	34 mm (1.3 inches)	87%	moderate
December Weather	-4°C (26°F)	42 mm (1.6 inches)	83%	moderate