Bynum, MT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Bynum, a community in Teton County, Montana.
Today
67°F
Partly Sunny
Partly sunny, with a high near 67. East northeast wind around 6 mph.
7-day forecast for Bynum
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 67°F | Partly Sunny | 6 mph ENE | 2% |
| Tonight | 45°F | Partly Cloudy | 2 to 6 mph S | 1% |
| Sunday | 73°F | Sunny | 2 to 6 mph S | 0% |
| Sunday Night | 46°F | Mostly Clear | 2 to 6 mph S | 0% |
| Monday | 77°F | Sunny | 5 mph SSW | 0% |
| Monday Night | 49°F | Mostly Clear | 5 mph WSW | 0% |
| Tuesday | 76°F | Sunny | 3 mph WSW | 0% |
| Tuesday Night | 49°F | Mostly Clear | 5 mph W | 0% |
| Wednesday | 77°F | Sunny | 2 to 7 mph SW | 2% |
| Wednesday Night | 50°F | Mostly Clear | 5 mph WSW | 3% |
| Thursday | 77°F | Mostly Sunny | 3 to 7 mph SSW | 3% |
| Thursday Night | 49°F | Partly Cloudy | 2 to 7 mph SSW | 11% |
| Friday | 71°F | Mostly Sunny | 3 to 9 mph WSW | 9% |
| Friday Night | 45°F | Chance Light Rain | 8 mph WNW | 27% |
Forecast source: National Weather Service (api.weather.gov) for Bynum (47.968, -112.316). Updated through the day.
Growing snapshot for Bynum
Last spring frost
May 16
First fall frost
Sep 27
Growing season
133 days
Hardiness zone
4b
More local growing data for Bynum: nearby ZIP 59419 weather · frost dates · planting calendar · Montana frost dates
Nearby towns & communities
Augusta
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Pendroy
Power
Rockport Colony
Climate data from the nearest NOAA station, Bynum 4 Sse, Mt (3 mi from Bynum). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.