Mammoth, MT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Mammoth, a community in Madison County, Montana.
This Afternoon
60°F
Showers And Thunderstorms
Showers and thunderstorms. Mostly cloudy. High near 60, with temperatures falling to around 57 in the afternoon. Northeast wind around 7 mph. Chance of precipitation is 90%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast for Mammoth
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 60°F | Showers And Thunderstorms | 7 mph NE | 89% |
| Tonight | 47°F | Showers And Thunderstorms | 3 to 8 mph ENE | 100% |
| Saturday | 49°F | Showers And Thunderstorms | 3 to 7 mph N | 97% |
| Saturday Night | 44°F | Rain Likely | 2 to 6 mph ESE | 66% |
| Sunday | 60°F | Partly Sunny | 5 mph W | 9% |
| Sunday Night | 44°F | Mostly Clear | 5 mph S | 0% |
| Monday | 64°F | Sunny | 5 mph SW | 0% |
| Monday Night | 47°F | Mostly Clear | 3 mph SW | 1% |
| Tuesday | 65°F | Mostly Sunny | 5 mph WSW | 2% |
| Tuesday Night | 47°F | Partly Cloudy | 5 mph SSW | 4% |
| Wednesday | 66°F | Sunny | 8 mph SW | 2% |
| Wednesday Night | 47°F | Mostly Clear | 6 mph SSW | 2% |
| Thursday | 68°F | Sunny | 7 mph SW | 3% |
| Thursday Night | 49°F | Mostly Clear | 5 to 9 mph S | 1% |
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 Sep 18, 2026.