Thief River Falls, MN Weather & Growing Conditions
Tonight
39°F
Cloudy then Slight Chance Light Rain
A slight chance of rain after midnight. Cloudy. Low around 39, with temperatures rising to around 41 overnight. North wind around 16 mph. Chance of precipitation is 20%.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 39°F | Cloudy then Slight Chance Light Rain | 16 mph N | 22% |
| Wednesday | 48°F | Slight Chance Light Rain then Cloudy | 18 mph N | 21% |
| Wednesday Night | 32°F | Mostly Cloudy | 14 to 17 mph N | 0% |
| Thursday | 40°F | Partly Sunny | 8 to 15 mph NNE | 0% |
| Thursday Night | 25°F | Partly Cloudy | 6 mph ESE | 0% |
| Friday | 42°F | Mostly Sunny | 3 to 10 mph S | 0% |
| Friday Night | 29°F | Partly Cloudy | 8 to 12 mph SSW | 0% |
| Saturday | 51°F | Mostly Sunny | 12 to 15 mph SW | 8% |
| Saturday Night | 33°F | Partly Cloudy | 8 to 12 mph W | 14% |
| Sunday | 51°F | Mostly Sunny | 8 to 12 mph WSW | 3% |
| Sunday Night | 36°F | Mostly Cloudy | 8 to 14 mph SSW | 0% |
| Monday | 53°F | Mostly Sunny | 14 to 21 mph WSW | 1% |
| Monday Night | 33°F | Mostly Clear | 7 to 14 mph W | 0% |
| Tuesday | 48°F | Mostly Sunny | 7 to 10 mph WNW | 0% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Thief River Falls, MN
Last spring frost
May 14
First fall frost
Sep 28
Growing season
135 days
Hardiness zone
4a
Explore more for Thief River Falls, MN: full frost dates · planting calendar · Minnesota frost dates
Climate data from the nearest NOAA station, Thief Rvr Falls 2, Mn (1.2 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.