Cornell, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 0.5 °C (low) to 11.9 °C (high). Annual precipitation averages 803.4 Millimeters. Cornell is located in USDA Plant Hardiness Zone 4b. 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 | -15.7 °C | -5.2 °C | 25.65 mm |
| February | -14.2 °C | -2.5 °C | 24.38 mm |
| March | -7.3 °C | 4.2 °C | 39.62 mm |
| April | 0.1 °C | 12.1 °C | 70.87 mm |
| May | 6.8 °C | 19.5 °C | 93.73 mm |
| June | 12.3 °C | 24.3 °C | 113.03 mm |
| July | 14.7 °C | 26.7 °C | 95.25 mm |
| August | 13.3 °C | 25.6 °C | 102.87 mm |
| September | 8.8 °C | 21.3 °C | 88.65 mm |
| October | 2.4 °C | 13.7 °C | 74.93 mm |
| November | -4.2 °C | 4.8 °C | 43.69 mm |
| December | -11.2 °C | -2.3 °C | 30.73 mm |
| Annual | 0.5 °C | 11.9 °C | 803.4 mm |
| 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 4b : -31.7°C to -28.9°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |