Click on a day for an hourly weather forecast
The temperatures in Knoxville in September are comfortable with low of 12°C and and high up to 26°C.
You can expect about 3 to 8 days of rain in Knoxville 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 Knoxville in September 2025.
If you’re planning to visit Knoxville in the near future, we highly recommend that you review the 14 day weather forecast for Knoxville before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 7° / -4° | 9 | 13 | 10 | 165 mm | Awful | Knoxville in January |
| February | 9° / -1° | 10 | 10 | 8 | 179 mm | Awful | Knoxville in February |
| March | 14° / 3° | 10 | 17 | 4 | 178 mm | Bad | Knoxville in March |
| April | 19° / 6° | 10 | 19 | 1 | 169 mm | Ok | Knoxville in April |
| May | 24° / 10° | 9 | 22 | 0 | 156 mm | Good | Knoxville in May |
| June | 28° / 13° | 10 | 20 | 0 | 164 mm | Good | Knoxville in June |
| July | 30° / 15° | 11 | 20 | 0 | 222 mm | Ok | Knoxville in July |
| August | 29° / 14° | 8 | 23 | 0 | 158 mm | Ok | Knoxville in August |
| September | 26° / 12° | 6 | 24 | 0 | 155 mm | Perfect | Knoxville in September |
| October | 20° / 7° | 6 | 25 | 1 | 126 mm | Good | Knoxville in October |
| November | 14° / 2° | 6 | 22 | 2 | 138 mm | Ok | Knoxville in November |
| December | 10° / 0° | 8 | 18 | 5 | 183 mm | Awful | Knoxville in December |