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The temperatures in Mammoth Lakes in September are quite cold with temperatures between 6°C and 20°C, warm clothes are a must.
The wather in Mammoth Lakes in September can vary between cold and nice weather days. Expect a few rainy days but usually not more than 3.
Our weather forecast can give you a great sense of what weather to expect in Mammoth Lakes in September 2025.
If you’re planning to visit Mammoth Lakes in the near future, we highly recommend that you review the 14 day weather forecast for Mammoth Lakes before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 2° / -9° | 6 | 19 | 6 | 86 mm | Awful | Mammoth Lakes in January |
| February | 1° / -10° | 7 | 16 | 5 | 78 mm | Awful | Mammoth Lakes in February |
| March | 3° / -8° | 7 | 17 | 7 | 72 mm | Awful | Mammoth Lakes in March |
| April | 8° / -4° | 5 | 21 | 4 | 37 mm | Bad | Mammoth Lakes in April |
| May | 12° / 0° | 6 | 22 | 2 | 37 mm | Bad | Mammoth Lakes in May |
| June | 19° / 5° | 5 | 25 | 0 | 22 mm | Good | Mammoth Lakes in June |
| July | 24° / 10° | 6 | 25 | 0 | 16 mm | Perfect | Mammoth Lakes in July |
| August | 24° / 9° | 4 | 27 | 0 | 14 mm | Perfect | Mammoth Lakes in August |
| September | 20° / 6° | 2 | 27 | 0 | 9 mm | Good | Mammoth Lakes in September |
| October | 14° / 1° | 2 | 28 | 1 | 29 mm | Good | Mammoth Lakes in October |
| November | 7° / -5° | 5 | 22 | 4 | 42 mm | Bad | Mammoth Lakes in November |
| December | 1° / -10° | 8 | 17 | 6 | 99 mm | Awful | Mammoth Lakes in December |