Kewaunee, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2.7 °C (low) to 10.9 °C (high). Annual precipitation averages 776.7 Millimeters. Kewaunee is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -10.9 °C | -3.3 °C | 37.08 mm |
| February | -10.1 °C | -1.7 °C | 27.43 mm |
| March | -4.9 °C | 3.3 °C | 39.88 mm |
| April | 1 °C | 9.1 °C | 72.14 mm |
| May | 6.6 °C | 15.4 °C | 84.07 mm |
| June | 12 °C | 21 °C | 95.25 mm |
| July | 15.3 °C | 24.3 °C | 84.33 mm |
| August | 15.4 °C | 24 °C | 89.15 mm |
| September | 11.2 °C | 19.9 °C | 75.69 mm |
| October | 5 °C | 13 °C | 75.95 mm |
| November | -1.1 °C | 6.1 °C | 57.66 mm |
| December | -7.1 °C | -0.1 °C | 38.1 mm |
| Annual | 2.7 °C | 10.9 °C | 776.73 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |