Forty Mile Colony, MT Weather & Growing Conditions
Tonight
29°F
Clear
Clear, with a low around 29. South southwest wind 2 to 7 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 29°F | Clear | 2 to 7 mph SSW | 0% |
| Wednesday | 52°F | Sunny | 5 mph W | 0% |
| Wednesday Night | 31°F | Partly Cloudy | 2 to 6 mph SSW | 0% |
| Thursday | 57°F | Mostly Sunny | 0 to 6 mph NNW | 0% |
| Thursday Night | 33°F | Partly Cloudy | 0 to 3 mph WSW | 2% |
| Friday | 57°F | Sunny | 5 mph SSW | 2% |
| Friday Night | 36°F | Partly Cloudy | 2 to 7 mph SSW | 6% |
| Saturday | 61°F | Sunny | 2 to 7 mph WSW | 2% |
| Saturday Night | 37°F | Mostly Clear | 2 to 8 mph S | 0% |
| Sunday | 69°F | Mostly Sunny | 2 to 8 mph WSW | 0% |
| Sunday Night | 40°F | Partly Cloudy | 5 mph SW | 0% |
| Monday | 60°F | Mostly Sunny | 5 mph ESE | 0% |
| Monday Night | 38°F | Mostly Cloudy | 5 mph SSE | 1% |
| Tuesday | 63°F | Mostly Sunny | 3 mph W | 2% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Forty Mile Colony, MT
Last spring frost
May 21
First fall frost
Sep 17
Growing season
117 days
Hardiness zone
5a
Explore more for Forty Mile Colony, MT: full frost dates · planting calendar · Montana frost dates
Climate data from the nearest NOAA station, Wyola 1 Sw, Mt (10.1 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.