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
63°F
Showers And Thunderstorms
Showers and thunderstorms. Cloudy. High near 63, with temperatures falling to around 61 in the afternoon. Northwest wind 8 to 13 mph. Chance of precipitation is 90%.
7-day forecast for Fort Smith
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 63°F | Showers And Thunderstorms | 8 to 13 mph NW | 94% |
| Tonight | 48°F | Patchy Fog | 10 to 16 mph WNW | 86% |
| Sunday | 63°F | Rain Showers | 12 mph WNW | 88% |
| Sunday Night | 47°F | Chance Rain Showers then Mostly Cloudy | 2 to 6 mph WSW | 28% |
| Monday | 73°F | Mostly Sunny | 1 to 5 mph SE | 4% |
| Monday Night | 49°F | Mostly Clear | 6 mph S | 0% |
| Tuesday | 79°F | Sunny | 5 mph SE | 0% |
| Tuesday Night | 53°F | Partly Cloudy then Slight Chance Rain Showers | 6 mph S | 15% |
| Wednesday | 80°F | Mostly Sunny | 6 mph WNW | 7% |
| Wednesday Night | 53°F | Partly Cloudy | 5 to 9 mph S | 5% |
| Thursday | 83°F | Sunny | 7 mph SW | 1% |
| Thursday Night | 53°F | Mostly Clear | 3 to 7 mph SSE | 1% |
| Friday | 83°F | Mostly Sunny | 7 mph SW | 0% |
| Friday Night | 53°F | Partly Cloudy | 3 to 9 mph SSW | 11% |
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 Sep 19, 2026.