Westby, MT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Westby, a town in Sheridan County, Montana.
Overnight
28°F
Patchy Fog
Patchy fog. Mostly clear. Low around 28, with temperatures rising to around 30 overnight. Southwest wind around 3 mph.
7-day forecast for Westby
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 28°F | Patchy Fog | 3 mph SW | 0% |
| Wednesday | 51°F | Patchy Fog then Sunny | 3 to 10 mph NW | 0% |
| Wednesday Night | 25°F | Partly Cloudy | 2 to 8 mph NE | 0% |
| Thursday | 46°F | Partly Sunny | 5 to 13 mph SE | 0% |
| Thursday Night | 30°F | Partly Cloudy | 9 mph S | 0% |
| Friday | 51°F | Sunny | 8 to 14 mph SW | 0% |
| Friday Night | 33°F | Partly Cloudy | 9 to 13 mph SW | 0% |
| Saturday | 54°F | Mostly Sunny | 16 to 21 mph W | 0% |
| Saturday Night | 30°F | Partly Cloudy | 5 to 9 mph SW | 0% |
| Sunday | 58°F | Mostly Sunny | 6 to 16 mph S | 0% |
| Sunday Night | 37°F | Mostly Cloudy | 12 to 16 mph W | 0% |
| Monday | 54°F | Mostly Sunny | 15 to 18 mph W | 0% |
| Monday Night | 30°F | Partly Cloudy | 5 to 8 mph W | 1% |
| Tuesday | 54°F | Mostly Sunny | 6 to 10 mph S | 2% |
Forecast source: National Weather Service (api.weather.gov) for Westby (48.870, -104.057). Updated through the day.
Growing snapshot for Westby
Last spring frost
May 18
First fall frost
Sep 21
Growing season
125 days
Hardiness zone
3b
More local growing data for Westby: nearby ZIP 59275 weather · frost dates · planting calendar · Montana frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Westby, Mt (4.8 mi from Westby). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.