Click on a day for an hourly weather forecast
The temperatures in Naperville in September are comfortable with low of 15°C and and high up to 24°C.
You can expect about 3 to 8 days of rain in Naperville 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 Naperville in September 2025.
If you’re planning to visit Naperville in the near future, we highly recommend that you review the 14 day weather forecast for Naperville before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | -2° / -8° | 5 | 12 | 14 | 44 mm | Awful | Naperville in January |
| February | -1° / -7° | 3 | 12 | 13 | 49 mm | Awful | Naperville in February |
| March | 7° / 0° | 6 | 18 | 7 | 60 mm | Bad | Naperville in March |
| April | 13° / 5° | 6 | 21 | 3 | 86 mm | Bad | Naperville in April |
| May | 20° / 12° | 7 | 24 | 0 | 112 mm | Ok | Naperville in May |
| June | 26° / 17° | 7 | 23 | 0 | 121 mm | Good | Naperville in June |
| July | 28° / 20° | 6 | 25 | 0 | 116 mm | Perfect | Naperville in July |
| August | 27° / 19° | 6 | 25 | 0 | 103 mm | Perfect | Naperville in August |
| September | 24° / 15° | 4 | 26 | 0 | 69 mm | Perfect | Naperville in September |
| October | 16° / 9° | 5 | 25 | 0 | 71 mm | Good | Naperville in October |
| November | 8° / 2° | 5 | 21 | 4 | 41 mm | Bad | Naperville in November |
| December | 2° / -3° | 5 | 16 | 10 | 43 mm | Awful | Naperville in December |