Deerfield, Wisconsin has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 3 °C (low) to 13.7 °C (high). Annual precipitation averages 949.7 Millimeters. Deerfield 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. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -11.7 °C | -2.8 °C | 38.35 mm |
| February | -10.1 °C | -0.6 °C | 40.13 mm |
| March | -4.2 °C | 6.2 °C | 52.58 mm |
| April | 2.2 °C | 13.8 °C | 95 mm |
| May | 8.7 °C | 20.7 °C | 109.98 mm |
| June | 14.1 °C | 25.8 °C | 136.4 mm |
| July | 16.6 °C | 28 °C | 108.2 mm |
| August | 15.5 °C | 27 °C | 106.17 mm |
| September | 10.8 °C | 23.2 °C | 88.9 mm |
| October | 4.2 °C | 15.6 °C | 73.15 mm |
| November | -1.9 °C | 7.4 °C | 56.13 mm |
| December | -7.9 °C | 0.3 °C | 44.7 mm |
| Annual | 3 °C | 13.7 °C | 949.69 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |