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.
This Afternoon
60°F
Partly Sunny
Partly sunny. High near 60, with temperatures falling to around 53 in the afternoon. Northeast wind around 5 mph.
7-day forecast for Forty Mile Colony
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 60°F | Partly Sunny | 5 mph NE | 0% |
| Tonight | 30°F | Mostly Cloudy | 3 to 7 mph SSE | 0% |
| Thursday | 57°F | Sunny | 6 mph N | 0% |
| Thursday Night | 33°F | Mostly Cloudy | 2 to 6 mph SW | 10% |
| Friday | 55°F | Sunny | 3 mph SW | 1% |
| Friday Night | 33°F | Mostly Clear | 2 to 7 mph SSE | 0% |
| Saturday | 61°F | Sunny | 1 to 5 mph SSW | 0% |
| Saturday Night | 35°F | Mostly Clear | 1 to 7 mph SE | 0% |
| Sunday | 68°F | Mostly Sunny | 0 to 7 mph SSW | 0% |
| Sunday Night | 37°F | Partly Cloudy | 2 mph S | 0% |
| Monday | 60°F | Mostly Sunny | 1 to 5 mph SE | 0% |
| Monday Night | 35°F | Mostly Cloudy | 3 mph SSE | 0% |
| Tuesday | 63°F | Mostly Sunny | 2 mph WNW | 1% |
| Tuesday Night | 37°F | Partly Cloudy | 0 to 5 mph W | 1% |
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 Nov 5, 2026.