Dayton
Ohio, USA
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Dayton, OH

The Maimi and Mad rivers converge to flow through Dayton city, Ohio, viewed from above
The Maimi and Mad rivers converge to flow through Dayton city, Ohio, viewed from above
The first month of the autumn, September, is also a moderately hot month in Dayton, Ohio, with average temperature varying between 54.9°F (12.7°C) and 75.9°F (24.4°C).

Temperature

In Dayton, the average high-temperature marginally drops, from 82.6°F (28.1°C) in August, to a still warm 75.9°F (24.4°C). In September, the average low-temperature is 54.9°F (12.7°C).

Humidity

The average relative humidity is 71.9%.

Rainfall

In Dayton, during September, the rain falls for 8.7 days and regularly aggregates up to 3.3" (83.8mm) of precipitation. In Dayton, during the entire year, the rain falls for 135.8 days and collects up to 41" (1042.5mm) of precipitation.

Snowfall

In Dayton, Ohio, it doesn't snow. In October, it regularly snows. In Dayton, during the entire year, snow aggregates up to 23.3" (591.9mm).

Daylight

The average length of the day in September is 12.4h.

Sunshine

In September, the average sunshine is 7.9h.

UV index

In Dayton, the average daily maximum UV index in September is 7. A UV Index estimate of 6 to 7 represents a high health hazard from the exposure to the Sun's UV radiation for the average person.
The average daily UV index of 7 in September transform into the following instructions:
Take precautions and utilize sun safety practices. Protection against the skin and eye damage is required. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.

What is the temperature in September in Dayton?

In September, the average high-temperature is 75.9°F (24.4°C), and the average low-temperature is 54.9°F (12.7°C).

What is the average humidity in September in Dayton?

In September, the average relative humidity is 71.9%.

How much does it rain in Dayton in September?

In Dayton, in September, during 8.7 rainfall days, 3.3" (83.8mm) of precipitation is typically accumulated.

Does it snow in Dayton in September?

In Dayton, Ohio, in September, it doesn't snow. In October, it regularly snows.

How many hours of daylight does Dayton have in September?

The average length of the day in September in Dayton is 12.4h.

How long on average sun shines in September in Dayton?

The average sunshine in September in Dayton, Ohio, is 7.9h.

How high is the UV index in September in Dayton?

The average daily maximum UV index in September is 7. A UV Index reading of 6 to 7 represents a high health risk from the exposure to the Sun's UV rays.
Average temperature in September - Dayton, OH
  • Average high temperature in September: 75.9°F

The warmest month (with the highest average high temperature) is July (83.8°F).
The month with the lowest average high temperature is January (34.7°F).

  • Average low temperature in September: 54.9°F

The month with the highest average low temperature is July (64.5°F).
The coldest month (with the lowest average low temperature) is January (20.3°F).

Average humidity in September - Dayton, OH
  • Average humidity in September: 71.9%

The month with the highest relative humidity is December (75.8%).
The month with the lowest relative humidity is April (64.2%).

Average rainfall in September - Dayton, OH
  • Average rainfall in September: 3.3"

The wettest month (with the highest rainfall) is May (4.7").
The driest month (with the lowest rainfall) is February (2.2").

Average rainfall days in September - Dayton, OH
  • Average rainfall days in September: 8.7 days

The month with the highest number of rainy days is May (13.7 days).
The month with the lowest number of rainy days is August (8.4 days).

Average snowfall in September - Dayton, OH
  • Average snowfall in September: 0"

The month with the highest snowfall is January (7.9").
Months with the lowest snowfall are May, June, July, August and September (0").

Average snowfall days in September - Dayton, OH
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (6.3 days).
Months with the lowest number of snowfall days are May, June, July, August and September (0 days).

Average daylight in September / Average sunshine in September - Dayton, OH
  • Average daylight in September: 12.4h

The month with the longest days is June (Average daylight: 15h).
The month with shortest days is December (Average daylight: 9.4h).

  • Average sunshine in September: 7.9h

The month with most sunshine is June (Average sunshine: 9.8h).
The month with least sunshine is December (Average sunshine: 3.2h).

Average UV index in September - Dayton, OH
  • Average UV index in September: 7

Months with the highest UV index are June and July (UV index 9).
Months with the lowest UV index are January, November and December (UV index 2).