Wilton, North Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -1.1 °C (low) to 10.9 °C (high). Annual precipitation averages 486.7 Millimeters. Wilton 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 | -17.1 °C | -6.8 °C | 12.95 mm |
| February | -15.1 °C | -4.4 °C | 11.43 mm |
| March | -8.6 °C | 2.7 °C | 17.53 mm |
| April | -1.2 °C | 11 °C | 31.24 mm |
| May | 5.4 °C | 18.3 °C | 68.33 mm |
| June | 10.9 °C | 23.4 °C | 91.95 mm |
| July | 13.9 °C | 27 °C | 79.25 mm |
| August | 12.6 °C | 26.8 °C | 56.64 mm |
| September | 7.3 °C | 21.3 °C | 46.74 mm |
| October | 0.2 °C | 12.2 °C | 35.05 mm |
| November | -7.4 °C | 3 °C | 16 mm |
| December | -13.7 °C | -4.1 °C | 19.56 mm |
| Annual | -1.1 °C | 10.9 °C | 486.67 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | Over 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 | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |