September Weather in Normal, United States

Last updated: June 24, 2025

The average temperature in Normal, United States during September is 21°C (70°F), with a minimum dropping to 5°C (41°F) and a maximum soaring to 35°C (95°F). Expect a total precipitation of 62 mm (2.4 in) over 7 days, while the humidity hovers around a comfortable 80%. Enjoy the dynamic weather that keeps each day interesting!

September Temperature in Normal

In September in Normal, the average temperature is 21°C (70°F). Maximums can reach 35°C (95°F), while minimums can drop to 5°C (41°F). This variability in temperature makes it essential for travelers to pack both lightweight clothing for the warm days and warmer layers for the cooler evenings.

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

The chart illustrates September temperature patterns in Normal, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Normal, September typically has an average temperature of 21°C (70°F), with highs reaching up to 35°C (95°F) and lows dropping to around 5°C (41°F).

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

September Precipitation in Normal

In Normal in September, the total precipitation amount is 62 mm (2.4 in) observed over a span of 7 days.

September Precipitation Trends in Normal

The chart displays monthly precipitation patterns in Normal, 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 Normal, September typically receives around 62 mm (2.4 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 Normal

In Normal in September humidity is 80%. With an average temperature of 21°C (70°F), this humidity feels like a warm, enveloping blanket that can make even short walks feel draining, urging travelers to seek shade or a cool drink frequently.

September Average Humidity in Normal

This chart illustrates the average monthly humidity levels in Normal, 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 Normal is approximately 80%, 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 Normal

In Normal 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 Normal.

Maximum UV Index Levels in Normal for September

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

Data source: Normal 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 Normal Compares to Other Months

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

This table compares monthly weather conditions in Normal, 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 (27°F)	65 mm (2.5 inches)	82%	moderate
February Weather	-1°C (30°F)	69 mm (2.7 inches)	83%	moderate
March Weather	5°C (42°F)	113 mm (4.4 inches)	84%	high
April Weather	11°C (51°F)	118 mm (4.6 inches)	85%	very high
May Weather	18°C (64°F)	159 mm (6.3 inches)	79%	very high
June Weather	23°C (74°F)	119 mm (4.7 inches)	82%	extreme
July Weather	25°C (77°F)	105 mm (4.1 inches)	80%	very high
August Weather	23°C (74°F)	94 mm (3.7 inches)	81%	very high
September Weather	21°C (70°F)	62 mm (2.4 inches)	80%	very high
October Weather	13°C (56°F)	125 mm (4.9 inches)	82%	high
November Weather	5°C (41°F)	62 mm (2.4 inches)	88%	moderate
December Weather	1°C (35°F)	55 mm (2.2 inches)	84%	low