Grass Range, MT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Grass Range, a town in Fergus County, Montana.
Tonight
53°F
Slight Chance Light Rain then Showers And Thunderstorms Likely
A slight chance of rain between 10pm and midnight, then showers and thunderstorms likely. Cloudy, with a low around 53. North wind 6 to 9 mph. Chance of precipitation is 70%. New rainfall amounts between a quarter and half of an inch possible.
7-day forecast for Grass Range
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 53°F | Slight Chance Light Rain then Showers And Thunderstorms Likely | 6 to 9 mph N | 65% |
| Saturday | 59°F | Rain then Showers And Thunderstorms | 8 to 12 mph N | 84% |
| Saturday Night | 51°F | Rain | 6 to 9 mph N | 79% |
| Sunday | 63°F | Light Rain Likely | 7 mph NNE | 66% |
| Sunday Night | 48°F | Mostly Cloudy | 5 to 8 mph SE | 9% |
| Monday | 74°F | Mostly Sunny | 5 to 12 mph SSE | 0% |
| Monday Night | 51°F | Mostly Clear | 8 to 13 mph S | 0% |
| Tuesday | 79°F | Mostly Sunny | 6 mph WNW | 0% |
| Tuesday Night | 54°F | Partly Cloudy | 7 mph S | 2% |
| Wednesday | 79°F | Sunny | 7 mph WSW | 2% |
| Wednesday Night | 54°F | Mostly Clear | 8 mph S | 1% |
| Thursday | 80°F | Sunny | 6 to 10 mph S | 2% |
| Thursday Night | 55°F | Mostly Clear | 10 mph S | 3% |
| Friday | 81°F | Mostly Sunny | 7 to 10 mph SSW | 1% |
Forecast source: National Weather Service (api.weather.gov) for Grass Range (47.026, -108.803). Updated through the day.
Growing snapshot for Grass Range
Last spring frost
May 20
First fall frost
Sep 24
Growing season
126 days
Hardiness zone
4b
More local growing data for Grass Range: nearby ZIP 59032 weather · frost dates · planting calendar · Montana frost dates
Nearby towns & communities
Ayers Ranch Colony
Brooks
Coffee Creek
Deerfield Colony
Denton
Fords Creek Colony
Hilger
King Ranch Colony
Lewistown
Lewistown Heights
Moore
Roy
Warm Spring Creek
Winifred
Climate data from the nearest NOAA station, Grass Range, Mt (4.7 mi from Grass Range). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.