Wilton, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 34.7 °F (low) to 55.1 °F (high). Annual precipitation averages 37.5 Inches. Wilton is located in USDA Plant Hardiness Zone 4b. 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 | 7.2 °F | 25.0 °F | 1.22 in. |
| February | 10.2 °F | 29.8 °F | 1.15 in. |
| March | 21.6 °F | 41.8 °F | 1.92 in. |
| April | 33.5 °F | 55.8 °F | 3.83 in. |
| May | 45.5 °F | 67.9 °F | 4.65 in. |
| June | 55.5 °F | 77.2 °F | 5.3 in. |
| July | 59.5 °F | 81.2 °F | 4.49 in. |
| August | 57.1 °F | 79.1 °F | 4.66 in. |
| September | 48.6 °F | 71.8 °F | 3.92 in. |
| October | 37.0 °F | 58.5 °F | 2.85 in. |
| November | 25.6 °F | 43.2 °F | 1.99 in. |
| December | 14.5 °F | 30.4 °F | 1.54 in. |
| Annual | 34.7 °F | 55.1 °F | 37.52 in. |
| 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 4b : -25°F to -20°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |