Plum City, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 1.7 °C (low) to 12.7 °C (high). Annual precipitation averages 896.6 Millimeters. Plum City 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 Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -14.7 °C | -4.7 °C | 25.15 mm |
| February | -12.7 °C | -1.9 °C | 26.92 mm |
| March | -5.8 °C | 4.9 °C | 47.24 mm |
| April | 1.2 °C | 13.2 °C | 80.26 mm |
| May | 8 °C | 20.1 °C | 113.03 mm |
| June | 13.8 °C | 25.3 °C | 134.87 mm |
| July | 16.1 °C | 27.7 °C | 106.68 mm |
| August | 14.8 °C | 26.5 °C | 120.14 mm |
| September | 10.3 °C | 22.5 °C | 97.03 mm |
| October | 3.3 °C | 14.7 °C | 67.31 mm |
| November | -3.7 °C | 5.6 °C | 44.45 mm |
| December | -10.4 °C | -1.8 °C | 33.53 mm |
| Annual | 1.7 °C | 12.7 °C | 896.61 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| 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 |