Click on a day for an hourly weather forecast
The temperatures in Ithaca in September are comfortable with low of 10°C and and high up to 21°C.
You can expect about 3 to 8 days of rain in Ithaca during the month of September. It’s a good idea to bring along your umbrella so that you don’t get caught in poor weather.
Our weather forecast can give you a great sense of what weather to expect in Ithaca in September 2025.
If you’re planning to visit Ithaca in the near future, we highly recommend that you review the 14 day weather forecast for Ithaca before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | -3° / -9° | 5 | 5 | 22 | 99 mm | Awful | Ithaca in January |
| February | -1° / -8° | 5 | 4 | 21 | 112 mm | Awful | Ithaca in February |
| March | 4° / -4° | 8 | 8 | 15 | 116 mm | Awful | Ithaca in March |
| April | 11° / 2° | 11 | 12 | 8 | 147 mm | Awful | Ithaca in April |
| May | 19° / 8° | 10 | 21 | 1 | 162 mm | Ok | Ithaca in May |
| June | 23° / 12° | 9 | 21 | 0 | 184 mm | Good | Ithaca in June |
| July | 26° / 14° | 10 | 21 | 0 | 171 mm | Good | Ithaca in July |
| August | 25° / 14° | 8 | 23 | 0 | 163 mm | Good | Ithaca in August |
| September | 21° / 10° | 7 | 23 | 0 | 148 mm | Ok | Ithaca in September |
| October | 14° / 6° | 9 | 20 | 2 | 133 mm | Bad | Ithaca in October |
| November | 7° / -1° | 8 | 12 | 10 | 93 mm | Awful | Ithaca in November |
| December | 1° / -4° | 6 | 7 | 18 | 114 mm | Awful | Ithaca in December |