September Weather in Herrin, United States

Last updated: June 24, 2025

In September, the average temperature in Herrin, United States is a pleasant 23°C (74°F). Expect a range from a cool 9°C (48°F) to a warm 35°C (96°F). Be prepared for an average precipitation of 74 mm (2.9 in) spread over 7 days, and keep in mind that humidity levels can reach around 75%.

September Temperature in Herrin

In September in Herrin, the average temperature is 23°C (74°F). Maximums can reach 35°C (96°F), while minimums can drop as low as 9°C (48°F). Overall, this month offers a warm climate, making it an ideal time for outdoor activities and exploration.

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

The chart illustrates September temperature patterns in Herrin, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Herrin, September typically has an average temperature of 23°C (74°F), with highs reaching up to 35°C (96°F) and lows dropping to around 9°C (48°F).

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

September Precipitation in Herrin

In Herrin in September, the precipitation amount is 74 mm (2.9 in) over a period of 7 days.

September Precipitation Trends in Herrin

The chart displays monthly precipitation patterns in Herrin, 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 Herrin, September typically receives around 74 mm (2.9 inches) of precipitation spread over approximately 7 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 Herrin

In Herrin 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 Herrin

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

In Herrin in September, the maximum UV index is 9, which corresponds to a very high Exposure Category. The time to burn is just 15 minutes, so it's essential to take precautions. For detailed information, you can check the Hourly UV Index in Herrin.

Maximum UV Index Levels in Herrin for September

The chart shows the monthly maximum UV Index (UVI) for Herrin 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 Herrin typically reaches 9, which falls under the very high exposure category.

Data source: Herrin 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 Herrin Compares to Other Months

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

This table compares monthly weather conditions in Herrin, 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 (36°F)	98 mm (3.9 inches)	86%	moderate
February Weather	4°C (39°F)	118 mm (4.7 inches)	84%	moderate
March Weather	10°C (49°F)	141 mm (5.6 inches)	84%	high
April Weather	14°C (57°F)	142 mm (5.6 inches)	80%	very high
May Weather	20°C (69°F)	138 mm (5.4 inches)	82%	extreme
June Weather	25°C (77°F)	108 mm (4.2 inches)	83%	extreme
July Weather	27°C (81°F)	92 mm (3.6 inches)	79%	very high
August Weather	25°C (78°F)	81 mm (3.2 inches)	76%	very high
September Weather	23°C (74°F)	74 mm (2.9 inches)	75%	very high
October Weather	16°C (61°F)	114 mm (4.5 inches)	74%	high
November Weather	8°C (46°F)	94 mm (3.7 inches)	85%	moderate
December Weather	5°C (42°F)	88 mm (3.4 inches)	88%	moderate