Westerville, Nebraska has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 36 °F (low) to 61.6 °F (high). Annual precipitation averages 25.3 Inches. Westerville is located in USDA Plant Hardiness Zone 5a. 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 | 12.3 °F | 36.2 °F | 0.5 in. |
| February | 15.3 °F | 39.6 °F | 0.66 in. |
| March | 24.4 °F | 50.9 °F | 1.38 in. |
| April | 34.2 °F | 60.7 °F | 2.89 in. |
| May | 45.6 °F | 70.6 °F | 4.04 in. |
| June | 56.7 °F | 81.1 °F | 3.79 in. |
| July | 61.8 °F | 86.6 °F | 3.21 in. |
| August | 59.4 °F | 84.6 °F | 3.04 in. |
| September | 49.1 °F | 77.2 °F | 2.17 in. |
| October | 35.6 °F | 64.1 °F | 1.93 in. |
| November | 23.3 °F | 49.8 °F | 0.95 in. |
| December | 14.8 °F | 38.2 °F | 0.7 in. |
| Annual | 36 °F | 61.6 °F | 25.26 in. |
| 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 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |