Heartwell, Nebraska has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 3.8 °C (low) to 17 °C (high). Annual precipitation averages 666.8 Millimeters. Heartwell is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -9.4 °C | 2.2 °C | 13.21 mm |
| February | -7.8 °C | 4.3 °C | 16.76 mm |
| March | -2.8 °C | 10.8 °C | 36.07 mm |
| April | 2.8 °C | 16.7 °C | 64.77 mm |
| May | 9.2 °C | 22.4 °C | 111.51 mm |
| June | 15.3 °C | 28.4 °C | 98.3 mm |
| July | 17.9 °C | 30.9 °C | 95 mm |
| August | 16.6 °C | 29.6 °C | 82.8 mm |
| September | 11.3 °C | 25.9 °C | 50.04 mm |
| October | 3.9 °C | 18.7 °C | 52.32 mm |
| November | -3.1 °C | 10.7 °C | 26.92 mm |
| December | -8 °C | 3.9 °C | 19.05 mm |
| Annual | 3.8 °C | 17 °C | 666.75 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |