Willow Island, Nebraska has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 2.9 °C (low) to 17.3 °C (high). Annual precipitation averages 603.7 Millimeters. Willow Island 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 | -9.9 °C | 3.3 °C | 10.16 mm |
| February | -8.3 °C | 5.3 °C | 15.75 mm |
| March | -3.3 °C | 11.4 °C | 29.97 mm |
| April | 1.8 °C | 16.6 °C | 62.48 mm |
| May | 8.1 °C | 22.2 °C | 100.84 mm |
| June | 14.2 °C | 28.2 °C | 90.17 mm |
| July | 16.9 °C | 31 °C | 87.88 mm |
| August | 15.7 °C | 29.7 °C | 78.23 mm |
| September | 10.3 °C | 25.9 °C | 43.43 mm |
| October | 2.8 °C | 18.7 °C | 48.26 mm |
| November | -4.1 °C | 10.9 °C | 21.84 mm |
| December | -8.9 °C | 4.6 °C | 14.73 mm |
| Annual | 2.9 °C | 17.3 °C | 603.74 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 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 | Severe Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |