September Weather in Westbrook, United States

Last updated: June 24, 2025

In Westbrook, United States, the average temperature for September is a comfortable 18°C (64°F). This month can bring variability, with temperatures dipping as low as 2°C (37°F) and peaking at a warm 32°C (90°F). Expect 110 mm (4.3 in) of precipitation spread over about 9 days, and enjoy the mild climate with an average humidity of 75%.

September Temperature in Westbrook

In September in Westbrook, the average temperature is 18°C (64°F). The maximum can reach 32°C (90°F), and the minimum can be as low as 2°C (37°F). It's a great time to visit Westbrook, as you can enjoy pleasantly warm days while being prepared for cooler evenings.

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

The chart illustrates September temperature patterns in Westbrook, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Westbrook, September typically has an average temperature of 18°C (64°F), with highs reaching up to 32°C (90°F) and lows dropping to around 2°C (37°F).

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

September Precipitation in Westbrook

In Westbrook in September, the precipitation amount is 110 mm (4.3 in) over the course of 9 days.

September Precipitation Trends in Westbrook

The chart displays monthly precipitation patterns in Westbrook, 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 Westbrook, September typically receives around 110 mm (4.3 inches) of precipitation spread over approximately 9 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 Westbrook

In Westbrook in September, humidity is 75%. With an average temperature of 18°C (64°F), this humidity feels like a warm blanket enveloping you, making your travels a bit sticky and requiring frequent breaks in the shade to stay comfortable.

September Average Humidity in Westbrook

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

In Westbrook 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 Westbrook.

Maximum UV Index Levels in Westbrook for September

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

Data source: Westbrook 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 Westbrook Compares to Other Months

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

This table compares monthly weather conditions in Westbrook, 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 (17°F)	29 mm (1.1 inches)	80%	moderate
February Weather	-9°C (17°F)	28 mm (1.1 inches)	84%	moderate
March Weather	0°C (33°F)	66 mm (2.6 inches)	75%	high
April Weather	6°C (43°F)	86 mm (3.4 inches)	79%	very high
May Weather	15°C (59°F)	127 mm (5.0 inches)	74%	very high
June Weather	22°C (72°F)	124 mm (4.9 inches)	81%	very high
July Weather	23°C (74°F)	119 mm (4.7 inches)	82%	very high
August Weather	21°C (70°F)	124 mm (4.9 inches)	80%	very high
September Weather	18°C (64°F)	110 mm (4.3 inches)	75%	very high
October Weather	9°C (48°F)	96 mm (3.8 inches)	77%	moderate
November Weather	1°C (34°F)	31 mm (1.2 inches)	85%	moderate
December Weather	-4°C (25°F)	42 mm (1.6 inches)	83%	low