September Weather in Chester, United States

Last updated: June 24, 2025

In Chester, United States, the average temperature for September hovers around 23°C (74°F). You can expect a minimum chill at 13°C (56°F) and an occasional peak of 30°C (87°F). With 118 mm (4.6 in) of precipitation spread over 10 days, it's wise to keep an umbrella handy. Additionally, the average humidity sits at a comfortable 75%, making for a pleasantly warm climate!

September Temperature in Chester

In September in Chester, the average temperature is 23°C (74°F). Maximums can reach 30°C (87°F), and minimums can be as low as 13°C (56°F). This pleasant climate makes it an ideal time for travelers to explore all that Chester has to offer.

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

The chart illustrates September temperature patterns in Chester, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Chester, September typically has an average temperature of 23°C (74°F), with highs reaching up to 30°C (87°F) and lows dropping to around 13°C (56°F).

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

September Precipitation in Chester

In Chester in September, the total precipitation amount is 118 mm (4.6 in) over a span of 10 days.

September Precipitation Trends in Chester

The chart displays monthly precipitation patterns in Chester, 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 Chester, September typically receives around 118 mm (4.6 inches) of precipitation spread over approximately 10 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 Chester

In Chester in September, humidity is 75%. With an average temperature of 23°C (74°F), this humidity feels like a warm, heavy blanket wrapping around you, making it feel more sweltering than it actually is, which can be quite uncomfortable for traveling.

September Average Humidity in Chester

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

In Chester 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 Chester.

Maximum UV Index Levels in Chester for September

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

Data source: Chester 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 Chester Compares to Other Months

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

This table compares monthly weather conditions in Chester, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	3°C (37°F)	79 mm (3.1 inches)	84%	moderate
February Weather	4°C (39°F)	136 mm (5.3 inches)	83%	moderate
March Weather	7°C (45°F)	106 mm (4.2 inches)	83%	high
April Weather	12°C (54°F)	112 mm (4.4 inches)	81%	very high
May Weather	18°C (64°F)	139 mm (5.5 inches)	78%	very high
June Weather	23°C (74°F)	83 mm (3.3 inches)	79%	very high
July Weather	27°C (80°F)	143 mm (5.6 inches)	74%	very high
August Weather	26°C (79°F)	136 mm (5.3 inches)	72%	very high
September Weather	23°C (74°F)	118 mm (4.6 inches)	75%	very high
October Weather	18°C (65°F)	138 mm (5.4 inches)	81%	high
November Weather	10°C (50°F)	96 mm (3.8 inches)	85%	moderate
December Weather	6°C (42°F)	130 mm (5.1 inches)	84%	moderate