Roundup, MT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Roundup, a city in Musselshell County, Montana.
Today
76°F
Sunny
Sunny, with a high near 76. Northwest wind 2 to 7 mph.
7-day forecast for Roundup
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 76°F | Sunny | 2 to 7 mph NW | 0% |
| Tonight | 49°F | Partly Cloudy | 5 mph E | 2% |
| Wednesday | 87°F | Sunny | 7 mph WSW | 0% |
| Wednesday Night | 53°F | Mostly Clear | 1 to 7 mph N | 0% |
| Thursday | 93°F | Sunny | 3 to 9 mph W | 0% |
| Thursday Night | 57°F | Mostly Clear | 1 to 8 mph N | 0% |
| Friday | 99°F | Sunny | 2 to 8 mph WSW | 0% |
| Friday Night | 61°F | Mostly Clear | 3 to 12 mph NNW | 0% |
| Saturday | 95°F | Sunny | 7 to 13 mph WNW | 0% |
| Saturday Night | 61°F | Mostly Clear | 3 to 12 mph NNE | 2% |
| Sunday | 93°F | Sunny | 3 to 12 mph N | 1% |
| Sunday Night | 61°F | Partly Cloudy | 6 to 12 mph NNE | 5% |
| Monday | 90°F | Mostly Sunny | 7 to 12 mph NNE | 4% |
| Monday Night | 61°F | Partly Cloudy | 7 to 12 mph NE | 13% |
Forecast source: National Weather Service (api.weather.gov) for Roundup (46.448, -108.540). Updated through the day.
Growing snapshot for Roundup
Last spring frost
May 20
First fall frost
Sep 21
Growing season
124 days
Hardiness zone
4b
More local growing data for Roundup: nearby ZIP 59072 weather · frost dates · planting calendar · Montana frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Roundup, Mt (6.2 mi from Roundup). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.