Plainfield, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 1.2 °C (low) to 12.4 °C (high). Annual precipitation averages 862.6 Millimeters. Plainfield 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 | -14.1 °C | -4.2 °C | 29.97 mm |
| February | -12.4 °C | -1.7 °C | 26.92 mm |
| March | -6.3 °C | 4.8 °C | 46.48 mm |
| April | 0.4 °C | 12.7 °C | 88.39 mm |
| May | 7.2 °C | 19.6 °C | 104.39 mm |
| June | 12.8 °C | 24.6 °C | 118.36 mm |
| July | 14.8 °C | 27 °C | 101.35 mm |
| August | 13.8 °C | 25.8 °C | 102.87 mm |
| September | 9.5 °C | 21.6 °C | 88.14 mm |
| October | 2.9 °C | 14.1 °C | 69.6 mm |
| November | -3.6 °C | 5.8 °C | 47.75 mm |
| December | -10.2 °C | -1.3 °C | 38.35 mm |
| Annual | 1.2 °C | 12.4 °C | 862.57 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 4b : -31.7°C to -28.9°C |
| Plant Hardiness Zone - 2012 | Zone 4b : -31.7°C to -28.9°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |