The weather in Mammoth 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 Mammoth 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 Mammoth during September. It’s important to get out your snow boots and warm mittens to stay warm while you explore Mammoth.
Our weather forecast can give you a great sense of what weather to expect in Mammoth in September 2025.
If you’re planning to visit Mammoth in the near future, we highly recommend that you review the 14 day weather forecast for Mammoth before you arrive.
Temperatures
16° / 3°
Rainy Days
6
Snowy Days
5
Dry Days
19
Rainfall
76
mm
Sun Hours
11.4
Hrs
