Nelsonville, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 1 °C (low) to 12.2 °C (high). Annual precipitation averages 851.7 Millimeters. Nelsonville is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -14 °C | -4.4 °C | 30.73 mm |
| February | -12.8 °C | -2 °C | 27.69 mm |
| March | -6.8 °C | 4.5 °C | 45.47 mm |
| April | 0.2 °C | 12.3 °C | 83.31 mm |
| May | 7 °C | 19.3 °C | 101.85 mm |
| June | 12.5 °C | 24.4 °C | 118.62 mm |
| July | 14.6 °C | 26.9 °C | 96.52 mm |
| August | 13.6 °C | 25.7 °C | 98.3 mm |
| September | 9 °C | 21.5 °C | 89.92 mm |
| October | 2.4 °C | 13.8 °C | 71.37 mm |
| November | -3.8 °C | 5.7 °C | 48.01 mm |
| December | -10.2 °C | -1.6 °C | 39.88 mm |
| Annual | 1 °C | 12.2 °C | 851.67 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -28.9°C to -26.1°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |