Thompson Falls, MT Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Thompson Falls, a city in Sanders County, Montana.
Overnight
40°F
Patchy Smoke
Patchy smoke. Mostly clear, with a low around 40. Wind around 0 mph.
7-day forecast for Thompson Falls
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 40°F | Patchy Smoke | 0 mph | 0% |
| Tuesday | 84°F | Patchy Smoke | 0 to 5 mph WNW | 0% |
| Tuesday Night | 45°F | Patchy Smoke then Mostly Clear | 0 to 5 mph NNW | 0% |
| Wednesday | 89°F | Sunny | 0 to 3 mph WNW | 0% |
| Wednesday Night | 48°F | Mostly Clear | 0 to 5 mph NW | 0% |
| Thursday | 97°F | Sunny | 0 to 5 mph W | 0% |
| Thursday Night | 53°F | Mostly Clear | 0 to 8 mph WNW | 0% |
| Friday | 96°F | Sunny | 0 to 10 mph WNW | 0% |
| Friday Night | 52°F | Mostly Clear | 2 to 12 mph SW | 0% |
| Saturday | 92°F | Sunny | 1 to 9 mph SW | 0% |
| Saturday Night | 51°F | Mostly Clear | 0 to 9 mph SSW | 0% |
| Sunday | 89°F | Sunny | 0 to 6 mph SW | 0% |
| Sunday Night | 49°F | Mostly Clear | 0 to 7 mph W | 0% |
| Monday | 89°F | Sunny | 0 to 3 mph NW | 0% |
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 Aug 4, 2026.