Mammoth, MT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Mammoth, a community in Madison County, Montana.
This Afternoon
44°F
Mostly Sunny
Mostly sunny. High near 44, with temperatures falling to around 38 in the afternoon. East southeast wind around 3 mph.
7-day forecast for Mammoth
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 44°F | Mostly Sunny | 3 mph ESE | 0% |
| Tonight | 30°F | Mostly Cloudy | 3 mph SSW | 0% |
| Wednesday | 44°F | Mostly Sunny | 2 mph SE | 0% |
| Wednesday Night | 29°F | Mostly Clear | 1 to 10 mph SSW | 0% |
| Thursday | 42°F | Mostly Sunny | 5 to 10 mph SW | 12% |
| Thursday Night | 27°F | Partly Cloudy | 5 to 10 mph SW | 12% |
| Friday | 42°F | Mostly Sunny | 8 to 12 mph SW | 6% |
| Friday Night | 29°F | Partly Cloudy | 8 to 18 mph SW | 6% |
| Saturday | 45°F | Mostly Sunny | 6 to 14 mph SW | 0% |
| Saturday Night | 33°F | Partly Cloudy | 6 to 16 mph SSW | 0% |
| Sunday | 50°F | Mostly Sunny | 8 to 16 mph SSW | 1% |
| Sunday Night | 35°F | Mostly Cloudy | 8 to 12 mph SSW | 1% |
| Monday | 48°F | Partly Sunny | 5 to 9 mph SSW | 2% |
| Monday Night | 37°F | Mostly Cloudy | 5 to 13 mph SSW | 2% |
Forecast source: National Weather Service (api.weather.gov) for Mammoth (45.669, -112.018). Updated through the day.
Growing snapshot for Mammoth
Last spring frost
Jun 8
First fall frost
Sep 2
Growing season
82 days
Hardiness zone
5a
More local growing data for Mammoth: nearby ZIP 59747 weather · frost dates · planting calendar · Montana frost dates
Nearby towns & communities
Alder
Big Sky
Brandon
Ennis
Harrison
Jeffers
McAllister
Norris
Pony
Sheridan
Silver Star
Twin Bridges
Virginia City
Climate data from the nearest NOAA station, Twin Bridges, Mt (20.4 mi from Mammoth). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 3, 2026.