Lena, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 33.8 °F (low) to 54.2 °F (high). Annual precipitation averages 33 Inches. Lena is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 7.9 °F | 25.2 °F | 1.57 in. |
| February | 9.1 °F | 28.8 °F | 1.16 in. |
| March | 19.4 °F | 39.9 °F | 1.86 in. |
| April | 31.7 °F | 53.2 °F | 3.16 in. |
| May | 43.6 °F | 66.5 °F | 3.53 in. |
| June | 53.7 °F | 75.7 °F | 4.17 in. |
| July | 58.0 °F | 80.4 °F | 3.79 in. |
| August | 56.1 °F | 78.5 °F | 3.39 in. |
| September | 48.0 °F | 71.0 °F | 3.47 in. |
| October | 36.7 °F | 57.4 °F | 3.08 in. |
| November | 26.1 °F | 43.1 °F | 2.04 in. |
| December | 14.8 °F | 30.4 °F | 1.81 in. |
| Annual | 33.8 °F | 54.2 °F | 33.03 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |