Wadena, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -0.8 °C (low) to 10.3 °C (high). Annual precipitation averages 695.2 Millimeters. Wadena is located in USDA Plant Hardiness Zone 4a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -18.3 °C | -7.8 °C | 17.27 mm |
| February | -16.4 °C | -4.9 °C | 17.78 mm |
| March | -8.9 °C | 2.1 °C | 31.75 mm |
| April | -1.2 °C | 10.9 °C | 56.13 mm |
| May | 6.1 °C | 18.3 °C | 89.15 mm |
| June | 12.1 °C | 23.2 °C | 108.97 mm |
| July | 14.6 °C | 25.9 °C | 108.71 mm |
| August | 13 °C | 25.1 °C | 77.47 mm |
| September | 8.3 °C | 20.4 °C | 69.85 mm |
| October | 1.2 °C | 12.1 °C | 69.85 mm |
| November | -6.1 °C | 2.9 °C | 27.94 mm |
| December | -13.7 °C | -4.8 °C | 20.32 mm |
| Annual | -0.8 °C | 10.3 °C | 695.19 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 4a : -34.4°C to -31.7°C |
| Plant Hardiness Zone - 2012 | Zone 3b : -37.2°C to -34.4°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |