Westby, MT Weather & Growing Conditions
Today
71°F
Mostly Sunny
Mostly sunny, with a high near 71. West northwest wind 12 to 17 mph, with gusts as high as 26 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 71°F | Mostly Sunny | 12 to 17 mph WNW | 0% |
| Tonight | 50°F | Partly Cloudy | 7 to 15 mph W | 2% |
| Wednesday | 79°F | Partly Sunny | 13 to 22 mph WSW | 6% |
| Wednesday Night | 52°F | Partly Cloudy | 6 to 17 mph W | 6% |
| Thursday | 83°F | Sunny | 7 to 15 mph W | 2% |
| Thursday Night | 54°F | Mostly Clear | 9 to 15 mph NNW | 1% |
| Friday | 79°F | Sunny | 9 mph NNE | 1% |
| Friday Night | 53°F | Partly Cloudy | 10 mph NE | 7% |
| Saturday | 81°F | Mostly Sunny | 8 to 13 mph NE | 0% |
| Saturday Night | 55°F | Partly Cloudy | 9 to 14 mph NE | 3% |
| Sunday | 78°F | Partly Sunny | 9 to 15 mph ENE | 11% |
| Sunday Night | 54°F | Slight Chance Showers And Thunderstorms | 12 to 16 mph ENE | 24% |
| Monday | 77°F | Slight Chance Rain Showers then Slight Chance Showers And Thunderstorms | 12 to 15 mph ENE | 18% |
| Monday Night | 54°F | Chance Showers And Thunderstorms | 10 to 15 mph ENE | 27% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Westby, MT
Last spring frost
May 18
First fall frost
Sep 21
Growing season
125 days
Hardiness zone
3b
Explore more for Westby, MT: full frost dates · planting calendar · Montana frost dates
Climate data from the nearest NOAA station, Westby, Mt (4.8 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.