Nielsville, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -0.9 °C (low) to 10.2 °C (high). Annual precipitation averages 611.6 Millimeters. Nielsville 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 | -18.9 °C | -9.2 °C | 21.34 mm |
| February | -16.8 °C | -6.4 °C | 18.8 mm |
| March | -9.1 °C | 0.7 °C | 25.91 mm |
| April | -0.7 °C | 10.8 °C | 35.56 mm |
| May | 6.3 °C | 18.8 °C | 72.39 mm |
| June | 12.8 °C | 24.3 °C | 104.14 mm |
| July | 14.7 °C | 26.7 °C | 89.41 mm |
| August | 13 °C | 26.3 °C | 70.36 mm |
| September | 8.1 °C | 21.3 °C | 71.88 mm |
| October | 1.3 °C | 12.5 °C | 54.1 mm |
| November | -6.8 °C | 2.6 °C | 22.86 mm |
| December | -14.3 °C | -5.9 °C | 24.89 mm |
| Annual | -0.9 °C | 10.2 °C | 611.64 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 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |