Willowbrook, Kansas has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 7.3 °C (low) to 19.6 °C (high). Annual precipitation averages 778.5 Millimeters. Willowbrook is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.8 °C | 5.9 °C | 20.32 mm |
| February | -4.1 °C | 7.9 °C | 30.48 mm |
| March | 1.3 °C | 13.9 °C | 56.39 mm |
| April | 6.4 °C | 19.1 °C | 65.53 mm |
| May | 12.4 °C | 24.6 °C | 128.02 mm |
| June | 18.2 °C | 30.4 °C | 109.98 mm |
| July | 20.4 °C | 32.8 °C | 92.71 mm |
| August | 19.4 °C | 31.8 °C | 91.19 mm |
| September | 14.8 °C | 27.8 °C | 58.93 mm |
| October | 7.6 °C | 20.9 °C | 62.48 mm |
| November | 0.9 °C | 13.5 °C | 34.04 mm |
| December | -4.3 °C | 6.8 °C | 28.45 mm |
| Annual | 7.3 °C | 19.6 °C | 778.52 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |