Hayward, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -0.9 °C (low) to 11.6 °C (high). Annual precipitation averages 843.8 Millimeters. Hayward is located in USDA Plant Hardiness Zone 4a. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -17.1 °C | -5.9 °C | 24.64 mm |
| February | -15.8 °C | -2.8 °C | 24.64 mm |
| March | -9 °C | 4.1 °C | 39.88 mm |
| April | -1.7 °C | 11.9 °C | 72.14 mm |
| May | 5.2 °C | 19.4 °C | 100.08 mm |
| June | 10.7 °C | 24.4 °C | 110.24 mm |
| July | 13.3 °C | 26.8 °C | 107.44 mm |
| August | 12 °C | 25.4 °C | 102.62 mm |
| September | 7.9 °C | 21.2 °C | 99.31 mm |
| October | 1.3 °C | 13.1 °C | 84.84 mm |
| November | -5.2 °C | 4.3 °C | 44.45 mm |
| December | -12.4 °C | -3 °C | 33.53 mm |
| Annual | -0.9 °C | 11.6 °C | 843.81 mm |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 4a : -34.4°C to -31.7°C |
| Plant Hardiness Zone - 2012 | Zone 3b : -37.2°C to -34.4°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |