September weather forecastDayton, OH
September
Weather in September
September marks the advent of fall in Dayton. The city's weather starts cooling significantly, providing a welcome relief from the summer heat. The daylight hours shorten, indicating a transitional phase. September also sees reduced rainfall, making it a preferable time for outdoor activities. The temperature range drops to 57°F (13.9°C) which signifies a marked departure from the soaring summer heat.Temperature
Dayton marks the arrival of September with an average high-temperature of a still warm 75°F (23.9°C), hardly different from August's 80.2°F (26.8°C). Dayton anticipates an average minimum temperature of 57°F (13.9°C) in the month of September.Humidity
In Dayton, the average relative humidity in September is 77%.Rainfall
September and November are months with the least rain when the rain falls for 12.5 days and typically aggregates up to 1.5" (38mm) of rain.Snowfall
May through September are months without snowfall.Daylight
In Dayton, the average length of the day in September is 12h and 26min.On the first day of the month, sunrise is at 7:05 am and sunset at 8:07 pm. On the last day of September, sunrise is at 7:32 am and sunset at 7:20 pm EDT.
Sunshine
The average sunshine in September in Dayton is 8.3h.UV index
In Dayton, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for the ordinary person.Note: The daily high UV index of 4 during September translates into the following recommendations:
Guard yourself - Avoiding sunburn is suggested. Avoiding the Sun during its peak radiation time around midday is a healthy practice. To best shield against UV radiation, choose sun-safe garments and dependable sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Dayton, OH
- Average high temperature in September: 75°F
The warmest month (with the highest average high temperature) is July (81.3°F).
The month with the lowest average high temperature is January (33.6°F).
- Average low temperature in September: 57°F
The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (21.7°F).
Average pressure in September
Dayton, OH
- Average pressure in September: 30.03"Hg
The month with the highest atmospheric pressure is November (30.14"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Dayton, OH
- Average wind speed in September: 6.3mph
The windiest month (with the highest average wind speed) is January (10mph).
The calmest month (with the lowest average wind speed) is August (5.7mph).
Average humidity in September
Dayton, OH
- Average humidity in September: 77%
The months with the highest relative humidity are January, February and December (82%).
The month with the lowest relative humidity is October (74%).
Average rainfall in September
Dayton, OH
- Average rainfall in September: 1.5"
The wettest month (with the highest rainfall) is May (3.35").
The driest months (with the least rainfall) are September and November (1.5").
Average rainfall days in September
Dayton, OH
- Average rainfall days in September: 12.5 days
The month with the highest number of rainy days is May (18.8 days).
The month with the least rainy days is February (7.5 days).
Average snowfall in September
Dayton, OH
- Average snowfall in September: 0"
The month with the highest snowfall is January (2.05").
The months with the least 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 (8.2 days).
The months with the least 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: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 54min).
The month with the shortest days is December (Average daylight: 9h and 24min).
- Average sunshine in September: 8h and 18min
The months with the most sunshine are June and July (Average sunshine: 10h and 12min).
The month with the least sunshine is January (Average sunshine: 3h and 42min).
Average sunshine days in September
Dayton, OH
- Average sunshine days in September: 16.1 days
The month with the most sunshine days is November (18.9 days).
The month with the least sunshine days is May (9.8 days).
Average UV index in September
Dayton, OH
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 2).
Average cloud cover in September
Dayton, OH
- Average cloud cover in September: 33
The month with the most cloud cover is January (Cloud cover 61).
The month with the least cloud cover is August (Cloud cover 29).
Average visibility in September
Dayton, OH
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
