Hallam, Nebraska has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 40.5 °F (low) to 62.5 °F (high). Annual precipitation averages 30.4 Inches. Hallam is located in USDA Plant Hardiness Zone 6a. 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 | 15.2 °F | 35.5 °F | 0.69 in. |
| February | 19.2 °F | 39.3 °F | 0.89 in. |
| March | 28.2 °F | 51.6 °F | 1.66 in. |
| April | 39.2 °F | 63.0 °F | 2.65 in. |
| May | 50.3 °F | 72.5 °F | 5.43 in. |
| June | 61.2 °F | 82.8 °F | 4.45 in. |
| July | 65.2 °F | 86.4 °F | 3.87 in. |
| August | 63.2 °F | 85.3 °F | 3.27 in. |
| September | 54.5 °F | 78.5 °F | 2.84 in. |
| October | 41.6 °F | 66.3 °F | 2.29 in. |
| November | 28.7 °F | 50.6 °F | 1.3 in. |
| December | 19.2 °F | 38.4 °F | 1.06 in. |
| Annual | 40.5 °F | 62.5 °F | 30.4 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°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 |