Lewis, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 32.5 °F (low) to 53.6 °F (high). Annual precipitation averages 32.8 Inches. Lewis 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 | 2.8 °F | 21.8 °F | 0.86 in. |
| February | 6.0 °F | 27.3 °F | 0.89 in. |
| March | 18.6 °F | 39.9 °F | 1.59 in. |
| April | 31.3 °F | 54.2 °F | 2.84 in. |
| May | 44.0 °F | 67.9 °F | 3.87 in. |
| June | 54.0 °F | 76.9 °F | 4.49 in. |
| July | 58.4 °F | 81.2 °F | 4.18 in. |
| August | 56.2 °F | 79.2 °F | 4.26 in. |
| September | 48.3 °F | 71.0 °F | 3.47 in. |
| October | 36.4 °F | 56.9 °F | 3.21 in. |
| November | 23.5 °F | 40.1 °F | 1.88 in. |
| December | 10.7 °F | 27.1 °F | 1.26 in. |
| Annual | 32.5 °F | 53.6 °F | 32.8 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 4a : -30°F to -25°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |