Fort Smith, MT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Fort Smith, a community in Big Horn County, Montana.
Today
77°F
Patchy Smoke
Patchy smoke. Sunny. High near 77, with temperatures falling to around 75 in the afternoon. East wind 1 to 12 mph.
7-day forecast for Fort Smith
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 77°F | Patchy Smoke | 1 to 12 mph E | 1% |
| Tonight | 52°F | Patchy Smoke | 3 to 12 mph ESE | 10% |
| Wednesday | 87°F | Sunny | 3 to 9 mph NW | 0% |
| Wednesday Night | 58°F | Mostly Clear | 5 to 8 mph SSW | 0% |
| Thursday | 96°F | Sunny | 1 to 9 mph W | 0% |
| Thursday Night | 62°F | Mostly Clear | 3 to 9 mph S | 0% |
| Friday | 100°F | Sunny | 2 to 7 mph WNW | 0% |
| Friday Night | 65°F | Mostly Clear | 9 mph SW | 0% |
| Saturday | 97°F | Sunny | 6 to 12 mph NW | 0% |
| Saturday Night | 65°F | Mostly Clear | 5 to 9 mph SE | 0% |
| Sunday | 96°F | Sunny | 6 to 10 mph NNW | 0% |
| Sunday Night | 65°F | Partly Cloudy | 6 to 10 mph E | 6% |
| Monday | 93°F | Mostly Sunny | 5 to 12 mph N | 2% |
| Monday Night | 64°F | Partly Cloudy | 7 to 12 mph E | 14% |
Forecast source: National Weather Service (api.weather.gov) for Fort Smith (45.317, -107.935). Updated through the day.
Growing snapshot for Fort Smith
Last spring frost
May 7
First fall frost
Oct 5
Growing season
151 days
Hardiness zone
5a
More local growing data for Fort Smith: nearby ZIP 59035 weather · frost dates · planting calendar · Montana frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Yellowtail Dam, Mt (0.8 mi from Fort Smith). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.