September Weather in Brookfield, United States

Last updated: June 24, 2025

In Brookfield, United States, the average temperature in September is a pleasant 18°C (65°F). Daytime highs can soar up to 33°C (91°F), while nighttime lows may dip to a cool 4°C (39°F). Expect around 96 mm (3.8 in) of precipitation over 8 days, contributing to an average humidity level of 71%. Whether you're planning outdoor adventures or cozy indoor moments, be prepared for a bit of everything!

September Temperature in Brookfield

In September in Brookfield, the average temperature is 18°C (65°F), with maximums reaching up to 33°C (91°F) and minimums dropping as low as 4°C (39°F). This range makes it an ideal time for travelers to enjoy both warm days and cool evenings while exploring the area.

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

The chart illustrates September temperature patterns in Brookfield, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Brookfield, September typically has an average temperature of 18°C (65°F), with highs reaching up to 33°C (91°F) and lows dropping to around 4°C (39°F).

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

September Precipitation in Brookfield

In Brookfield in September, the precipitation amount is 96 mm (3.8 in) over the course of 8 days.

September Precipitation Trends in Brookfield

The chart displays monthly precipitation patterns in Brookfield, 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 Brookfield, September typically receives around 96 mm (3.8 inches) of precipitation spread over approximately 8 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 Brookfield

In Brookfield in September humidity is 71%. With an average temperature of 18°C (65°F), this humidity feels like a warm embrace, making it a bit sticky and muggy, which can be slightly uncomfortable for traveling, especially if you're engaging in outdoor activities or exploring the city on foot.

September Average Humidity in Brookfield

This chart illustrates the average monthly humidity levels in Brookfield, 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 Brookfield is approximately 71%, 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 Brookfield

In Brookfield 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 Brookfield.

Maximum UV Index Levels in Brookfield for September

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

Data source: Brookfield 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 Brookfield Compares to Other Months

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

This table compares monthly weather conditions in Brookfield, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-2°C (29°F)	73 mm (2.9 inches)	86%	moderate
February Weather	-1°C (31°F)	90 mm (3.6 inches)	84%	moderate
March Weather	2°C (36°F)	87 mm (3.4 inches)	82%	high
April Weather	8°C (47°F)	130 mm (5.1 inches)	80%	very high
May Weather	14°C (58°F)	96 mm (3.8 inches)	72%	very high
June Weather	20°C (68°F)	94 mm (3.7 inches)	72%	very high
July Weather	23°C (73°F)	155 mm (6.1 inches)	67%	very high
August Weather	22°C (72°F)	100 mm (4.0 inches)	66%	very high
September Weather	18°C (65°F)	96 mm (3.8 inches)	71%	very high
October Weather	12°C (55°F)	141 mm (5.6 inches)	78%	high
November Weather	5°C (41°F)	100 mm (4.0 inches)	84%	moderate
December Weather	0°C (32°F)	126 mm (5.0 inches)	81%	low