Forsyth, MT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Forsyth, a city in Rosebud County, Montana.
Tonight
57°F
Chance Showers And Thunderstorms
A chance of showers and thunderstorms before 1am, then showers and thunderstorms. Mostly cloudy. Low around 57, with temperatures rising to around 59 overnight. North northeast wind around 7 mph. Chance of precipitation is 80%.
7-day forecast for Forsyth
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 57°F | Chance Showers And Thunderstorms | 7 mph NNE | 75% |
| Saturday | 64°F | Showers And Thunderstorms | 7 to 13 mph NE | 98% |
| Saturday Night | 53°F | Showers And Thunderstorms | 12 mph ENE | 97% |
| Sunday | 64°F | Rain Showers | 9 mph ENE | 87% |
| Sunday Night | 50°F | Chance Rain Showers then Mostly Cloudy | 6 mph E | 30% |
| Monday | 73°F | Partly Sunny | 3 to 7 mph SE | 2% |
| Monday Night | 50°F | Mostly Clear | 5 to 9 mph ESE | 0% |
| Tuesday | 79°F | Sunny | 3 mph SSE | 0% |
| Tuesday Night | 52°F | Partly Cloudy | 3 mph ESE | 5% |
| Wednesday | 81°F | Mostly Sunny | 3 mph SSW | 4% |
| Wednesday Night | 52°F | Mostly Clear | 2 mph ESE | 4% |
| Thursday | 82°F | Sunny | 1 to 5 mph SE | 2% |
| Thursday Night | 53°F | Partly Cloudy | 6 mph ESE | 2% |
| Friday | 82°F | Mostly Sunny | 6 mph SE | 4% |
Forecast source: National Weather Service (api.weather.gov) for Forsyth (46.268, -106.673). Updated through the day.
Growing snapshot for Forsyth
Last spring frost
May 9
First fall frost
Sep 29
Growing season
142 days
Hardiness zone
4b
More local growing data for Forsyth: nearby ZIP 59327 weather · frost dates · planting calendar · Montana frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Forsyth, Mt (2.5 mi from Forsyth). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.