Forty Mile Colony, MT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Forty Mile Colony, a community in Big Horn County, Montana.
Today
78°F
Patchy Smoke
Patchy smoke. Sunny, with a high near 78. East northeast wind 2 to 8 mph.
7-day forecast for Forty Mile Colony
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 78°F | Patchy Smoke | 2 to 8 mph ENE | 0% |
| Tonight | 50°F | Patchy Smoke then Mostly Clear | 8 mph ESE | 13% |
| Wednesday | 86°F | Sunny | 3 to 8 mph W | 0% |
| Wednesday Night | 54°F | Mostly Clear | 3 to 7 mph SSE | 0% |
| Thursday | 95°F | Sunny | 3 to 9 mph WSW | 0% |
| Thursday Night | 58°F | Mostly Clear | 5 to 8 mph ESE | 0% |
| Friday | 99°F | Sunny | 2 to 7 mph W | 0% |
| Friday Night | 61°F | Mostly Clear | 8 mph SSE | 0% |
| Saturday | 97°F | Sunny | 5 to 12 mph NW | 0% |
| Saturday Night | 61°F | Mostly Clear | 6 to 9 mph E | 0% |
| Sunday | 95°F | Mostly Sunny | 3 to 10 mph NNW | 0% |
| Sunday Night | 61°F | Partly Cloudy | 5 to 9 mph E | 5% |
| Monday | 93°F | Mostly Sunny | 3 to 12 mph N | 2% |
| Monday Night | 61°F | Slight Chance Showers And Thunderstorms then Partly Cloudy | 6 to 10 mph E | 16% |
Forecast source: National Weather Service (api.weather.gov) for Forty Mile Colony (45.283, -107.357). Updated through the day.
Growing snapshot for Forty Mile Colony
Last spring frost
May 21
First fall frost
Sep 17
Growing season
117 days
Hardiness zone
5a
More local growing data for Forty Mile Colony: nearby ZIP 59050 weather · frost dates · planting calendar · Montana frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Wyola 1 Sw, Mt (10.1 mi from Forty Mile Colony). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.