September Weather in Sterling, United States

Last updated: June 24, 2025

In September, the average temperature in Sterling, United States hovers around 11°C (51°F), with lows dipping to -3°C (26°F) and highs reaching up to 20°C (69°F). Rainfall can be expected, with 113 mm (4.4 in) spread over 16 days. The air is quite moist, boasting an average humidity of 97%.

September Temperature in Sterling

In September in Sterling, the average temperature is 11°C (51°F). Maximums can reach 20°C (69°F) and minimums can be as low as -3°C (26°F). This weather makes Sterling an ideal destination for travelers looking to enjoy a pleasant mix of mild and cool temperatures.

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

The chart illustrates September temperature patterns in Sterling, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Sterling, September typically has an average temperature of 11°C (51°F), with highs reaching up to 20°C (69°F) and lows dropping to around -3°C (26°F).

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

September Precipitation in Sterling

In Sterling in September, the precipitation amount is 113 mm (4.4 in) spread over 16 days.

September Precipitation Trends in Sterling

The chart displays monthly precipitation patterns in Sterling, 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 Sterling, September typically receives around 113 mm (4.4 inches) of precipitation spread over approximately 16 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 Sterling

In Sterling in September humidity is 97%. With an average temperature of 11°C (51°F), this humidity feels like wrapping yourself in a damp blanket, making travel quite uncomfortable and sticky, as the heavy air weighs you down and could easily dampen your enthusiasm for exploring.

September Average Humidity in Sterling

This chart illustrates the average monthly humidity levels in Sterling, 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 Sterling is approximately 97%, 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 Sterling

In Sterling in September, the maximum UV index reaches 4, which corresponds to a moderate Exposure Category. With a time to burn of 30 minutes, it’s important to take precautions to protect your skin. You can find more details in the Hourly UV Index in Sterling for better planning.

Maximum UV Index Levels in Sterling for September

The chart shows the monthly maximum UV Index (UVI) for Sterling 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 Sterling typically reaches 4, which falls under the moderate exposure category.

Data source: Sterling 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 Sterling Compares to Other Months

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

This table compares monthly weather conditions in Sterling, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-7°C (19°F)	53 mm (2.1 inches)	95%	low
February Weather	-5°C (23°F)	50 mm (1.9 inches)	95%	low
March Weather	-3°C (27°F)	39 mm (1.5 inches)	90%	moderate
April Weather	4°C (39°F)	36 mm (1.4 inches)	82%	moderate
May Weather	10°C (49°F)	67 mm (2.6 inches)	85%	high
June Weather	13°C (56°F)	66 mm (2.6 inches)	95%	high
July Weather	16°C (61°F)	75 mm (2.9 inches)	100%	high
August Weather	15°C (59°F)	98 mm (3.9 inches)	99%	high
September Weather	11°C (51°F)	113 mm (4.4 inches)	97%	moderate
October Weather	5°C (42°F)	127 mm (5.0 inches)	93%	low
November Weather	-2°C (28°F)	91 mm (3.6 inches)	97%	low
December Weather	-3°C (26°F)	110 mm (4.3 inches)	98%	low