Mammoth, MT Weather & Growing Conditions
This Afternoon
55°F
Showers And Thunderstorms
Showers and thunderstorms. Cloudy. High near 55, with temperatures falling to around 52 in the afternoon. South wind around 6 mph. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 55°F | Showers And Thunderstorms | 6 mph S | 84% |
| Tonight | 43°F | Showers And Thunderstorms | 5 to 10 mph NE | 100% |
| Saturday | 46°F | Showers And Thunderstorms | 7 mph NNE | 96% |
| Saturday Night | 42°F | Rain Likely | 6 mph WNW | 65% |
| Sunday | 53°F | Partly Sunny | 5 mph WNW | 9% |
| Sunday Night | 43°F | Mostly Clear | 5 mph SSW | 0% |
| Monday | 59°F | Sunny | 5 mph WSW | 0% |
| Monday Night | 47°F | Mostly Clear | 6 mph SW | 1% |
| Tuesday | 60°F | Mostly Sunny | 5 mph WSW | 2% |
| Tuesday Night | 47°F | Partly Cloudy | 6 mph SW | 4% |
| Wednesday | 61°F | Sunny | 7 mph SW | 2% |
| Wednesday Night | 47°F | Mostly Clear | 7 mph SSW | 2% |
| Thursday | 63°F | Sunny | 3 to 8 mph SW | 3% |
| Thursday Night | 48°F | Partly Cloudy | 5 to 12 mph S | 1% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Mammoth, MT
Last spring frost
Jun 8
First fall frost
Sep 2
Growing season
82 days
Hardiness zone
5a
Explore more for Mammoth, MT: full frost dates · planting calendar · Montana frost dates
Climate data from the nearest NOAA station, Twin Bridges, Mt (20.4 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.