Weather in Onondaga County, New York for September 2025
Until now, September 2025 in Onondaga County has been nearly identical to the historical average, with a temperature of 21.6 °F (showing only a slight deviation of -0.5 °F).
Expect cooler weather in the next days in Onondaga County with the forecast suggesting a temperature of 23.9 °F, lower than the historical average.
In general, the average temperature in Onondaga County at the beginning of September is 21.9 °F. As the month progressed, temperatures tended to noticeably warm up, reaching an average of 24.6 °F by the end of September.
Onondaga County experiences moderate rainfall in September, with an average of 8 rainy days and a total precipitation of 141.1 mm.
New! Chat with our AI weatherman - it’s amazing and free.
Temperatures
Rain 🌧️
More
Onondaga County Weather September
Temperatures trend during September in Onondaga County
September weather in Onondaga County day by day
| Date | Weather | Temperatures | Rain | UV | More |
|---|---|---|---|---|---|
| Sept. 1 |  Light rain shower | 24° /12° | 1.4 mm | 6 | |
| Sept. 2 | Patchy rain possible | 20° /10° | 0.2 mm | 5 | |
| Sept. 3 |  Partly cloudy | 22° /10° | 0 mm | 6 | |
| Sept. 4 |  Sunny | 23° /12° | 47.3 mm | 6 | |
| Sept. 5 | Sunny | 24° /10° | 0 mm | 6 | |
| Sept. 6 | Partly cloudy | 22° /11° | 12.6 mm | 6 | |
| Sept. 7 | Light rain shower | 18° /9° | 11.1 mm | 4 | |
| Sept. 8 | Patchy rain possible | 17° /7° | 0.1 mm | 4 | |
| Sept. 9 |  Moderate or heavy rain with thunder | 20° /8° | 4.2 mm | 5 | |
| Sept. 10 |  Mist | 20° /10° | 0 mm | 5 | |
| Sept. 11 |  Overcast | 23° /9° | 0 mm | 5 | |
| Sept. 12 | Partly cloudy | 25° /13° | 0 mm | 6 | |
| Sept. 13 | Sunny | 23° /14° | 0 mm | 6 | |
| Sept. 14 | Sunny | 24° /14° | 0 mm | 6 | |
| Sept. 15 |  Moderate rain at times | 24° /14° | 1 mm | 6 | |
| Sept. 16 | Partly cloudy | 25° /12° | 0 mm | 6 | |
| Sept. 17 |  Cloudy | 24° /14° | 0 mm | 6 | |
| Sept. 18 | Sunny | 25° /9° | 0 mm | 1.3 | |
| Sept. 19 | Overcast | 20° /8° | 0 mm | 1.3 | |
| Sept. 20 | Sunny | 21° /2° | 0 mm | 1.4 | |
| Sept. 21 | Cloudy | 26° /7° | 0 mm | 1.2 | |
| Sept. 22 | Patchy rain possible | 27° /14° | 1.7 mm | 0 | |
| Sept. 23 | Patchy rain possible | 29° /15° | 0.2 mm | 5 | |
| Sept. 24 | Mist | 24° /16° | 0.1 mm | 4 | |
| Sept. 25 | Patchy rain possible | 24° /17° | 0.3 mm | 4 | |
| Sept. 26 | Partly cloudy | 26° /16° | 0 mm | 6 | |
| Sept. 27 | Patchy rain possible | 25° /17° | 0.5 mm | 5 | |
| Sept. 28 | Partly cloudy | 29° /19° | 0.1 mm | 6 | |
| Sept. 29 | Patchy rain possible | 25° /14° | 1 mm | 4 | |
| Sept. 30 | Partly cloudy | 19° /12° | 0 mm | 4 | |
| Next | |||||
Onondaga County in September - FAQ
September rainfall patterns in Onondaga County
UV exposure in Onondaga County during September
Quick links
Where is Onondaga County?Get accurate weather forecasts for Onondaga County, located at latitude 43.048 and longitude -76.147. Stay updated with localized weather information tailored for Onondaga County.