Thompson Falls, MT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Thompson Falls, a city in Sanders County, Montana.
Today
80°F
Patchy Fog then Sunny
Patchy fog between 7am and 9am. Sunny, with a high near 80. South wind around 2 mph.
7-day forecast for Thompson Falls
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 80°F | Patchy Fog then Sunny | 2 mph S | 2% |
| Tonight | 46°F | Mostly Clear then Patchy Fog | 2 mph N | 3% |
| Sunday | 81°F | Areas Of Fog then Sunny | 0 to 3 mph NW | 0% |
| Sunday Night | 46°F | Mostly Clear | 1 mph NNW | 0% |
| Monday | 83°F | Sunny | 0 to 5 mph W | 0% |
| Monday Night | 47°F | Mostly Clear | 0 to 5 mph NW | 0% |
| Tuesday | 81°F | Sunny | 0 to 3 mph NW | 0% |
| Tuesday Night | 47°F | Partly Cloudy | 0 to 3 mph W | 1% |
| Wednesday | 79°F | Mostly Sunny | 0 to 6 mph SW | 0% |
| Wednesday Night | 46°F | Partly Cloudy | 0 to 3 mph SW | 3% |
| Thursday | 78°F | Mostly Sunny | 2 mph NW | 1% |
| Thursday Night | 46°F | Partly Cloudy | 2 mph NW | 4% |
| Friday | 74°F | Partly Sunny | 0 to 5 mph WSW | 10% |
| Friday Night | 44°F | Chance Light Rain | 1 to 5 mph WSW | 25% |
Forecast source: National Weather Service (api.weather.gov) for Thompson Falls (47.599, -115.343). Updated through the day.
Growing snapshot for Thompson Falls
Last spring frost
May 7
First fall frost
Oct 4
Growing season
150 days
Hardiness zone
6a
More local growing data for Thompson Falls: nearby ZIP 59873 weather · frost dates · planting calendar · Montana frost dates
Nearby towns & communities
Belknap
Bull Lake
Camas
Dixon
Heron
Hot Springs
Lonepine
Noxon
Old Agency
Paradise
Plains
Trout Creek
Climate data from the nearest NOAA station, Thompson Falls Ph, Mt (6.3 mi from Thompson Falls). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.