Deer River, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -1.5 °C (low) to 10.3 °C (high). Annual precipitation averages 688.8 Millimeters. Deer River is located in USDA Plant Hardiness Zone 3b. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -19.1 °C | -7.8 °C | 18.54 mm |
| February | -17.3 °C | -4.2 °C | 15.75 mm |
| March | -9.8 °C | 3.1 °C | 27.43 mm |
| April | -2.1 °C | 10.8 °C | 46.99 mm |
| May | 5.1 °C | 18.5 °C | 75.44 mm |
| June | 10.9 °C | 23.3 °C | 109.98 mm |
| July | 13.6 °C | 25.9 °C | 107.19 mm |
| August | 12.3 °C | 24.9 °C | 86.11 mm |
| September | 7.7 °C | 20.1 °C | 81.53 mm |
| October | 1.2 °C | 11.7 °C | 64.26 mm |
| November | -6.2 °C | 2.3 °C | 33.78 mm |
| December | -14.2 °C | -4.9 °C | 21.84 mm |
| Annual | -1.5 °C | 10.3 °C | 688.84 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 3b : -37.2°C to -34.4°C |
| Plant Hardiness Zone - 2012 | Zone 3b : -37.2°C to -34.4°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |