Click on a day for an hourly weather forecast
The temperatures in Gillette in September are comfortable with low of 12°C and and high up to 24°C.
You can expect about 3 to 8 days of rain in Gillette 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 Gillette in September 2025.
If you’re planning to visit Gillette in the near future, we highly recommend that you review the 14 day weather forecast for Gillette before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 0° / -8° | 7 | 21 | 3 | 17 mm | Awful | Gillette in January |
| February | 0° / -9° | 8 | 17 | 3 | 21 mm | Awful | Gillette in February |
| March | 8° / -3° | 5 | 22 | 3 | 34 mm | Bad | Gillette in March |
| April | 11° / 1° | 9 | 18 | 3 | 64 mm | Awful | Gillette in April |
| May | 18° / 7° | 11 | 20 | 0 | 98 mm | Ok | Gillette in May |
| June | 25° / 13° | 9 | 21 | 0 | 75 mm | Good | Gillette in June |
| July | 30° / 17° | 8 | 23 | 0 | 45 mm | Good | Gillette in July |
| August | 29° / 17° | 6 | 25 | 0 | 51 mm | Good | Gillette in August |
| September | 24° / 12° | 4 | 26 | 0 | 43 mm | Perfect | Gillette in September |
| October | 14° / 4° | 5 | 24 | 2 | 49 mm | Ok | Gillette in October |
| November | 7° / -2° | 5 | 23 | 2 | 19 mm | Bad | Gillette in November |
| December | 0° / -8° | 6 | 22 | 3 | 20 mm | Awful | Gillette in December |