| 2023 Hardiness Zone: | Zone 3b: -35°F to -30°F Zone 4a: -30°F to -25°F | |
| 2012 Hardiness Zone: | Zone 3b: -35°F to -30°F | |
| 1990 Hardiness Zone: | Zone 3b: -35F to -30F | |
| Average First Frost Date: | Sep. 21 - Sep. 30 | |
| Average Last Frost Date: | May 11 - May 20 | |
| Koppen-Geiger Climate Zone: | Dfb - Humid Continental Mild Summer, Wet All Year | |
| Ecoregion: | 48d - Lake Agassiz Plains | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | Rare Over 86°F |
Annual Climate Data for ZIP Code 56701 - Thief River Falls, MN | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | -6 | 1 | 15 | 29 | 43 | 52 | 56 | 54 | 44 | 33 | 17 | 1 | 28 |
| Avg Max Temp (°F) | 12 | 21 | 34 | 53 | 69 | 76 | 81 | 79 | 68 | 54 | 32 | 18 | 50 |
| Avg Precip (In.) | .62 | .5 | .82 | 1.24 | 2.5 | 3.64 | 3.54 | 3.24 | 2.47 | 1.81 | 1.01 | .55 | 21.96 |