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The weather in Wyoming in September is very cold with temperatures between 3°C and 16°C, warm clothes are a must.
You can expect about 3 to 8 days of rain in Wyoming 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.
You can expect a few days of snow in Wyoming during September. It’s important to get out your snow boots and warm mittens to stay warm while you explore Wyoming.
Our weather forecast can give you a great sense of what weather to expect in Wyoming in September 2025.
If you’re planning to visit Wyoming in the near future, we highly recommend that you review the 14 day weather forecast for Wyoming before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | -6° / -15° | 3 | 5 | 24 | 112 mm | Awful | Wyoming in January |
| February | -6° / -15° | 4 | 1 | 25 | 118 mm | Awful | Wyoming in February |
| March | -1° / -11° | 6 | 1 | 27 | 129 mm | Awful | Wyoming in March |
| April | 2° / -8° | 7 | 2 | 26 | 141 mm | Awful | Wyoming in April |
| May | 9° / -3° | 15 | 2 | 22 | 163 mm | Awful | Wyoming in May |
| June | 16° / 3° | 10 | 11 | 8 | 113 mm | Bad | Wyoming in June |
| July | 22° / 7° | 6 | 25 | 1 | 56 mm | Good | Wyoming in July |
| August | 21° / 6° | 7 | 23 | 1 | 67 mm | Ok | Wyoming in August |
| September | 16° / 3° | 6 | 19 | 5 | 76 mm | Ok | Wyoming in September |
| October | 6° / -4° | 7 | 7 | 17 | 94 mm | Awful | Wyoming in October |
| November | -2° / -10° | 4 | 6 | 21 | 100 mm | Awful | Wyoming in November |
| December | -7° / -16° | 3 | 3 | 25 | 111 mm | Awful | Wyoming in December |