September Weather in Dayton, United States

Last updated: June 24, 2025

In September, the average temperature in Dayton, United States reaches a warm 26°C (80°F). Expect a range between a cool 13°C (55°F) and a sizzling 38°C (100°F). This month typically sees about 217 mm (8.5 in) of precipitation spread over 14 days, alongside an average humidity of 73%.

September Temperature in Dayton

In September in Dayton, the average temperature is 26°C (80°F). Maximum can reach 38°C (100°F) and minimum can be as low as 13°C (55°F). This makes it a great time to explore Dayton, offering warm weather for outdoor activities while still being cool enough for comfortable sightseeing.

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

The chart illustrates September temperature patterns in Dayton, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Dayton, September typically has an average temperature of 26°C (80°F), with highs reaching up to 38°C (100°F) and lows dropping to around 13°C (55°F).

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

September Precipitation in Dayton

In Dayton in September, the precipitation amount is 217 mm (8.5 in) over a span of 14 days.

September Precipitation Trends in Dayton

The chart displays monthly precipitation patterns in Dayton, 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 Dayton, September typically receives around 217 mm (8.5 inches) of precipitation spread over approximately 14 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 Dayton

In Dayton in September, humidity is 73%. With an average temperature of 26°C (80°F), this humidity feels like a warm embrace that clings to your skin, making outdoor exploration a bit sticky but still inviting, perfect for leisurely strolls in the shade or refreshing breaks by the water.

September Average Humidity in Dayton

This chart illustrates the average monthly humidity levels in Dayton, 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 Dayton is approximately 73%, 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 Dayton

In Dayton 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 Dayton.

Maximum UV Index Levels in Dayton for September

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

Data source: Dayton 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 Dayton Compares to Other Months

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

This table compares monthly weather conditions in Dayton, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	12°C (54°F)	93 mm (3.7 inches)	78%	moderate
February Weather	14°C (58°F)	102 mm (4.0 inches)	81%	very high
March Weather	18°C (65°F)	100 mm (3.9 inches)	76%	very high
April Weather	21°C (69°F)	106 mm (4.2 inches)	79%	extreme
May Weather	25°C (77°F)	188 mm (7.4 inches)	79%	extreme
June Weather	27°C (81°F)	171 mm (6.7 inches)	74%	extreme
July Weather	28°C (83°F)	142 mm (5.6 inches)	71%	extreme
August Weather	28°C (83°F)	208 mm (8.2 inches)	68%	extreme
September Weather	26°C (80°F)	217 mm (8.5 inches)	73%	very high
October Weather	22°C (72°F)	116 mm (4.6 inches)	75%	very high
November Weather	16°C (62°F)	79 mm (3.1 inches)	78%	high
December Weather	14°C (58°F)	117 mm (4.6 inches)	84%	moderate