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
61°F
Rain Showers
Rain showers and patchy fog. Cloudy, with a high near 61. West northwest wind 8 to 13 mph. Chance of precipitation is 100%.
7-day forecast for Forty Mile Colony
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 61°F | Rain Showers | 8 to 13 mph WNW | 95% |
| Tonight | 45°F | Scattered Rain Showers then Areas Of Fog | 1 to 6 mph W | 51% |
| Monday | 72°F | Areas Of Fog then Mostly Sunny | 5 mph SE | 2% |
| Monday Night | 46°F | Mostly Clear | 8 mph SE | 0% |
| Tuesday | 80°F | Sunny | 2 to 6 mph ESE | 0% |
| Tuesday Night | 50°F | Partly Cloudy then Slight Chance Showers And Thunderstorms | 5 mph SE | 17% |
| Wednesday | 80°F | Slight Chance Rain Showers then Mostly Sunny | 6 mph W | 15% |
| Wednesday Night | 49°F | Mostly Clear | 2 to 6 mph S | 2% |
| Thursday | 84°F | Sunny | 6 mph NNE | 1% |
| Thursday Night | 51°F | Mostly Clear | 5 to 8 mph SE | 1% |
| Friday | 86°F | Sunny | 3 to 8 mph SE | 0% |
| Friday Night | 51°F | Mostly Clear | 2 to 6 mph SSE | 1% |
| Saturday | 79°F | Mostly Sunny | 8 mph W | 5% |
| Saturday Night | 45°F | Partly Cloudy | 5 to 8 mph ENE | 13% |
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 Sep 20, 2026.