McCool Junction, Nebraska has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 39.5 °F (low) to 62.6 °F (high). Annual precipitation averages 27.9 Inches. 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 | 13.9 °F | 34.4 °F | 0.6 in. |
| February | 17.8 °F | 39.2 °F | 0.66 in. |
| March | 27.3 °F | 51.7 °F | 1.4 in. |
| April | 37.7 °F | 63.0 °F | 2.54 in. |
| May | 50.0 °F | 73.2 °F | 5.02 in. |
| June | 60.8 °F | 83.2 °F | 4.16 in. |
| July | 65.0 °F | 87.1 °F | 3.34 in. |
| August | 62.6 °F | 84.8 °F | 3.55 in. |
| September | 53.3 °F | 78.7 °F | 2.48 in. |
| October | 40.4 °F | 66.1 °F | 2.07 in. |
| November | 27.4 °F | 51.0 °F | 1.21 in. |
| December | 18.1 °F | 38.2 °F | 0.84 in. |
| Annual | 39.5 °F | 62.6 °F | 27.87 in. |
| 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 : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |