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September Weather in Dayton, United States

Last updated: June 24, 2025

In September, the average temperature in Dayton, United States hovers around 21°C (71°F). Expect a range where the minimum can dip to 7°C (45°F) and the maximum can climb to a scorching 35°C (95°F). With an average humidity of 73%, be prepared for a sultry feel. Additionally, you can expect about 91 mm (3.6 in) of precipitation spread over 8 days throughout the month.

September Temperature in Dayton

In September in Dayton, the average temperature is 21°C (71°F). The maximum can reach 35°C (95°F), while the minimum can drop to as low as 7°C (45°F). This makes Dayton an ideal destination for travelers looking to enjoy a warm climate with refreshing cooler evenings.

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 21°C (71°F), with highs reaching up to 35°C (95°F) and lows dropping to around 7°C (45°F).
JanFebMarAprMayJunJulAugSepOctNovDec343746546673777570594439
Data source: Temperature data for Dayton generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

September Precipitation in Dayton

In Dayton in September, the total precipitation amount is 91 mm (3.6 in) over the course of 8 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 91 mm (3.6 inches) of precipitation spread over approximately 8 days.
JanFebMarAprMayJunJulAugSepOctNovDec8111213612913314811693919896114
Data source: Precipitation data for September generated using information from the Copernicus Climate Change Service.
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September Humidity in Dayton

In Dayton in September humidity is 73%. With an average temperature of 21°C (71°F), this humidity feels like a warm, enveloping blanket that can make outdoor activities a bit uncomfortable, but with proper hydration and breaks in the shade, it’s still manageable for traveling.

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.
JanFebMarAprMayJunJulAugSepOctNovDec88%88%87%85%81%82%81%73%73%78%89%87%
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 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 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 8, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec356910101098643
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.
 TemperaturePrecipitationHumidityUV
January Weather1°C (34°F)81 mm (3.2 inches)88%moderate
February Weather3°C (38°F)112 mm (4.4 inches)88%moderate
March Weather8°C (46°F)136 mm (5.3 inches)87%high
April Weather12°C (55°F)129 mm (5.1 inches)85%very high
May Weather19°C (66°F)132 mm (5.2 inches)81%very high
June Weather23°C (74°F)148 mm (5.8 inches)82%very high
July Weather25°C (78°F)116 mm (4.6 inches)81%very high
August Weather24°C (75°F)93 mm (3.7 inches)73%very high
September Weather21°C (71°F)91 mm (3.6 inches)73%very high
October Weather15°C (60°F)98 mm (3.9 inches)78%high
November Weather7°C (44°F)96 mm (3.8 inches)89%moderate
December Weather4°C (39°F)114 mm (4.5 inches)87%moderate

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