Plainfield, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 34.2 °F (low) to 54.3 °F (high). Annual precipitation averages 34 Inches. 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 | 6.7 °F | 24.5 °F | 1.18 in. |
| February | 9.7 °F | 29.0 °F | 1.06 in. |
| March | 20.6 °F | 40.7 °F | 1.83 in. |
| April | 32.8 °F | 54.8 °F | 3.48 in. |
| May | 44.9 °F | 67.3 °F | 4.11 in. |
| June | 55.0 °F | 76.2 °F | 4.66 in. |
| July | 58.6 °F | 80.6 °F | 3.99 in. |
| August | 56.8 °F | 78.4 °F | 4.05 in. |
| September | 49.1 °F | 70.8 °F | 3.47 in. |
| October | 37.2 °F | 57.3 °F | 2.74 in. |
| November | 25.6 °F | 42.4 °F | 1.88 in. |
| December | 13.7 °F | 29.6 °F | 1.51 in. |
| Annual | 34.2 °F | 54.3 °F | 33.96 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 |