McCool Junction, Nebraska has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.2 °C (low) to 17 °C (high). Annual precipitation averages 707.9 Millimeters. McCool Junction 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. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -10.1 °C | 1.3 °C | 15.24 mm |
| February | -7.9 °C | 4 °C | 16.76 mm |
| March | -2.6 °C | 10.9 °C | 35.56 mm |
| April | 3.2 °C | 17.2 °C | 64.52 mm |
| May | 10 °C | 22.9 °C | 127.51 mm |
| June | 16 °C | 28.4 °C | 105.66 mm |
| July | 18.3 °C | 30.6 °C | 84.84 mm |
| August | 17 °C | 29.3 °C | 90.17 mm |
| September | 11.8 °C | 25.9 °C | 62.99 mm |
| October | 4.7 °C | 18.9 °C | 52.58 mm |
| November | -2.6 °C | 10.6 °C | 30.73 mm |
| December | -7.7 °C | 3.4 °C | 21.34 mm |
| Annual | 4.2 °C | 17 °C | 707.9 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| 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 | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |