September Weather in Evanston, United States

Last updated: June 24, 2025

In Evanston, United States, the average temperature in September is a mild 14°C (58°F), with temperatures ranging from a minimum of -7°C (20°F) to a maximum of 32°C (90°F). Expect light precipitation, averaging 27 mm (1.0 in) over 6 days, while the average humidity hovers around 46%. It's a month that offers a mix of weather, perfect for exploring!

September Temperature in Evanston

In September, in Evanston, the average temperature is 14°C (58°F). The maximum can reach 32°C (90°F) and the minimum can be as low as -7°C (20°F). Be prepared for a wide range of temperatures to fully enjoy your travel experience.

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

The chart illustrates September temperature patterns in Evanston, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Evanston, September typically has an average temperature of 14°C (58°F), with highs reaching up to 32°C (90°F) and lows dropping to around -7°C (20°F).

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

September Precipitation in Evanston

In Evanston in September, the precipitation amount is 27 mm (1.0 in) over the course of 6 days.

September Precipitation Trends in Evanston

The chart displays monthly precipitation patterns in Evanston, 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 Evanston, September typically receives around 27 mm (1.0 inches) of precipitation spread over approximately 6 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 Evanston

In Evanston in September, humidity is 46%. With an average temperature of 14°C (58°F), this humidity feels like a refreshing yet slightly brisk breeze, making it quite pleasant for traveling as you can comfortably explore without feeling overheated.

September Average Humidity in Evanston

This chart illustrates the average monthly humidity levels in Evanston, 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 Evanston is approximately 46%, 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 Evanston

In Evanston in September, the maximum UV index reaches 10, which corresponds to a very high Exposure Category. With a time to burn of just 15 minutes, it's crucial to take precautions. For more detailed information, you can check the Hourly UV Index in Evanston.

Maximum UV Index Levels in Evanston for September

The chart shows the monthly maximum UV Index (UVI) for Evanston 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 Evanston typically reaches 10, which falls under the very high exposure category.

Data source: Evanston 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 Evanston Compares to Other Months

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

This table compares monthly weather conditions in Evanston, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-6°C (22°F)	43 mm (1.7 inches)	91%	moderate
February Weather	-5°C (24°F)	52 mm (2.1 inches)	92%	high
March Weather	0°C (32°F)	55 mm (2.2 inches)	84%	very high
April Weather	3°C (38°F)	50 mm (2.0 inches)	74%	very high
May Weather	9°C (48°F)	61 mm (2.4 inches)	62%	extreme
June Weather	16°C (61°F)	21 mm (0.8 inches)	56%	extreme
July Weather	21°C (70°F)	23 mm (0.9 inches)	44%	extreme
August Weather	19°C (67°F)	21 mm (0.8 inches)	37%	extreme
September Weather	14°C (58°F)	27 mm (1.0 inches)	46%	very high
October Weather	5°C (41°F)	35 mm (1.4 inches)	67%	high
November Weather	0°C (33°F)	43 mm (1.7 inches)	84%	moderate
December Weather	-5°C (23°F)	42 mm (1.7 inches)	88%	moderate