Thief River Falls, MN Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Thief River Falls, a city in Pennington County, Minnesota.
Tonight
51°F
Partly Cloudy
Partly cloudy. Low around 51, with temperatures rising to around 53 overnight. Southeast wind 3 to 8 mph.
7-day forecast for Thief River Falls
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 51°F | Partly Cloudy | 3 to 8 mph SE | 3% |
| Saturday | 69°F | Partly Sunny | 3 to 12 mph NE | 10% |
| Saturday Night | 48°F | Mostly Cloudy | 8 to 12 mph NE | 0% |
| Sunday | 65°F | Partly Sunny | 10 mph ENE | 0% |
| Sunday Night | 44°F | Mostly Cloudy | 8 mph E | 0% |
| Monday | 67°F | Sunny | 6 to 9 mph ESE | 0% |
| Monday Night | 41°F | Mostly Clear | 8 mph SE | 0% |
| Tuesday | 67°F | Sunny | 8 to 13 mph SSE | 0% |
| Tuesday Night | 45°F | Mostly Clear | 12 mph SSE | 1% |
| Wednesday | 68°F | Mostly Sunny | 12 to 16 mph SSE | 6% |
| Wednesday Night | 50°F | Partly Cloudy then Slight Chance Rain Showers | 12 mph SSE | 15% |
| Thursday | 71°F | Slight Chance Rain Showers then Mostly Sunny | 9 to 13 mph S | 15% |
| Thursday Night | 52°F | Mostly Clear | 9 mph SSE | 8% |
| Friday | 72°F | Mostly Sunny | 8 to 14 mph S | 8% |
Forecast source: National Weather Service (api.weather.gov) for Thief River Falls (48.111, -96.178). Updated through the day.
Growing snapshot for Thief River Falls
Last spring frost
May 14
First fall frost
Sep 28
Growing season
135 days
Hardiness zone
4a
More local growing data for Thief River Falls: nearby ZIP 56701 weather · frost dates · planting calendar · Minnesota frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Thief Rvr Falls 2, Mn (1.2 mi from Thief River Falls). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.