Lannon, Wisconsin has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 37 °F (low) to 56 °F (high). Annual precipitation averages 36.5 Inches. Lannon is located in USDA Plant Hardiness Zone 5b. 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 | 11.9 °F | 27.7 °F | 1.85 in. |
| February | 14.7 °F | 31.3 °F | 1.72 in. |
| March | 24.0 °F | 42.5 °F | 2.17 in. |
| April | 34.8 °F | 55.1 °F | 3.93 in. |
| May | 45.6 °F | 66.9 °F | 4.1 in. |
| June | 55.4 °F | 76.5 °F | 4.6 in. |
| July | 60.7 °F | 81.6 °F | 4.17 in. |
| August | 59.0 °F | 79.7 °F | 3.59 in. |
| September | 51.0 °F | 72.7 °F | 3.16 in. |
| October | 39.8 °F | 59.8 °F | 2.92 in. |
| November | 28.7 °F | 45.4 °F | 2.17 in. |
| December | 18.5 °F | 33.1 °F | 2.1 in. |
| Annual | 37 °F | 56 °F | 36.48 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 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |