Butternut, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 29.7 °F (low) to 50.8 °F (high). Annual precipitation averages 34.3 Inches. Butternut is located in USDA Plant Hardiness Zone 4a. 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 | 1.3 °F | 20.4 °F | 1.18 in. |
| February | 3.3 °F | 25.7 °F | 1.04 in. |
| March | 14.3 °F | 37.3 °F | 1.69 in. |
| April | 27.9 °F | 50.5 °F | 2.96 in. |
| May | 40.7 °F | 64.5 °F | 4.0 in. |
| June | 50.6 °F | 73.6 °F | 4.95 in. |
| July | 55.2 °F | 77.8 °F | 4.28 in. |
| August | 52.6 °F | 75.8 °F | 3.76 in. |
| September | 45.4 °F | 67.8 °F | 3.68 in. |
| October | 33.7 °F | 53.3 °F | 3.37 in. |
| November | 21.7 °F | 37.7 °F | 1.97 in. |
| December | 9.4 °F | 25.5 °F | 1.44 in. |
| Annual | 29.7 °F | 50.8 °F | 34.32 in. |
| 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 4a : -30°F to -25°F |
| Plant Hardiness Zone - 2012 | Zone 4a : -30°F to -25°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |