Dayton, OH weather in September
In September, Dayton sees highs around 79°F and lows around 56°F: mild, with some rain. Expect about 8 wet days. Good for outdoor plans.
- Normal high
- 79°F
- Normal low
- 56°F
- Wet days
- 8
- 3.0 in total
- Muggy days
- 4
- dew point 65°F+
How September changes from start to finish
| September 1 | September 30 | |
|---|---|---|
| Normal high | 84°F | 73°F |
| Normal low | 61°F | 50°F |
| Chance of a wet day | 26% | 27% |
| Sunrise / sunset | 7:04 am / 8:08 pm | 7:32 am / 7:21 pm |
| Daylight | 13.1 h | 11.8 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Eastern Time).
A typical September day
- 6 am58°Fdew point 55°F
- 9 am65°Fdew point 57°F
- Noon73°Fdew point 56°F
- 3 pm76°Fdew point 55°F
- 6 pm73°Fdew point 55°F
- 9 pm65°Fdew point 57°F
NOAA hourly normals (local standard time) from Wright Patterson AFB (9 mi away); average wind 6 mph; clear or few clouds in 45% of daytime hours, mostly cloudy or overcast in 41%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F12 of 30
- Hot dayshigh 90°F or more4 of 30
- Muggy daysdaily mean dew point 65°F or more4 of 30
- Wet daysat least 0.01 in of rain or melted snow8 of 30
- Notable rainat least 0.10 in5 of 30
- Freezing nightslow 32°F or below0 of 30
- Snow on the groundsnow depth 1 in or more0 of 30
Average days per September, counted from daily records for each year 1991-2020.
Rain in September
Normal precipitation is 3.0 in; a dry September brings about 1.4 in and a wet one about 4.0 in (25th and 75th percentiles). About 2 days bring half an inch or more, and about 1 an inch or more.
How September varies from year to year
- Warmest September, 1991-20202019: average high 89°F
- Coolest September2006: average high 73°F
- Wettest September2002: 8.4 in
- Driest September1998: 0.3 in
- Highest reading99°F (September 3, 2011)
- Lowest reading36°F (September 24, 1995)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
September compared with August and October
| August | September | October | |
|---|---|---|---|
| Normal high | 86°F | 79°F | 66°F |
| Normal low | 64°F | 56°F | 44°F |
| Wet days | 8 | 8 | 9 |
| Comfortable days | 4 | 12 | 14 |
| Daylight | 13.7 h | 12.4 h | 11.1 h |
Highs change by -7°F from August and -13°F into October.
Nearby alternatives in September
- Cooler: Lansing, MI206 mi · high 74°F · 10 wet days
How Dayton ranks in September
- Normal high208th warmest of 378 cities; 2nd of 6 in Ohio
- Wet days198th driest of 378
- Comfortable days138th most of 342
What to pack for Dayton in September
- A rain jacket or umbrella – rain on about 8 days
Heating and cooling
September has 67 heating degree days and 142 cooling degree days (base 65°F), 3% of the year's total heating and cooling demand.
Questions
How hot is Dayton in September?
The normal high is 79°F and the normal low is 56°F. From 1991 to 2020 the hottest September reading was 99°F (most recently on September 3, 2011).
Does it rain a lot in Dayton in September?
About 8 days in September have at least 0.01 in of precipitation, and the normal total is 3.0 in. The wettest September in 1991-2020 was in 2002 (8.4 in); the driest was in 1998 (0.3 in).
Is September a good time to visit Dayton?
September ranks 4th of 12 months on our comfort score for Dayton (62 out of 100). It has about 12 comfortable days and about 4 days at 90°F or hotter. The best months are April, May and October.
Where the numbers come from
- Temperature, rain and frost dates: Dayton Mcd (USC00332067), 0.3 mi N of the city center, 720 ft . NOAA normals and daily records, 1991-2020.
- Snowfall and snow depth: Dayton Intl Airport (USW00093815), 10 mi N of the city center, 1,000 ft (260 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Humidity and wind by hour and cloud cover: Wright Patterson AFB (USW00013840), 9.1 mi NE of the city center, 823 ft (83 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: J.m.cox Dayton International Airport (724290-93815), 10 mi N of the city center, 993 ft (253 ft higher than the city). Hourly observations, 1991-2020.