Delavan, Wisconsin has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 37.7 °F (low) to 57.2 °F (high). Annual precipitation averages 37.5 Inches. Delavan 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 | 13.0 °F | 28.5 °F | 1.68 in. |
| February | 15.6 °F | 32.2 °F | 1.69 in. |
| March | 25.2 °F | 44.1 °F | 2.14 in. |
| April | 35.4 °F | 57.3 °F | 3.74 in. |
| May | 47.2 °F | 68.6 °F | 4.27 in. |
| June | 56.7 °F | 78.4 °F | 5.33 in. |
| July | 61.0 °F | 82.1 °F | 3.65 in. |
| August | 59.3 °F | 80.7 °F | 4.15 in. |
| September | 51.4 °F | 74.0 °F | 3.56 in. |
| October | 39.9 °F | 61.0 °F | 2.93 in. |
| November | 29.2 °F | 46.2 °F | 2.42 in. |
| December | 18.9 °F | 33.6 °F | 1.91 in. |
| Annual | 37.7 °F | 57.2 °F | 37.47 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |