Union City, Ohio has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 41.2 °F (low) to 60.5 °F (high). Annual precipitation averages 40.7 Inches. Union City is located in USDA Plant Hardiness Zone 6a. 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 | 17.9 °F | 33.7 °F | 2.78 in. |
| February | 20.5 °F | 37.7 °F | 2.2 in. |
| March | 29.5 °F | 48.1 °F | 3.14 in. |
| April | 39.9 °F | 61.1 °F | 4.11 in. |
| May | 51.1 °F | 71.6 °F | 4.35 in. |
| June | 60.5 °F | 80.1 °F | 4.62 in. |
| July | 62.7 °F | 82.8 °F | 4.1 in. |
| August | 60.6 °F | 81.7 °F | 3.47 in. |
| September | 53.3 °F | 76.4 °F | 3.07 in. |
| October | 42.6 °F | 64.0 °F | 2.98 in. |
| November | 32.3 °F | 50.3 °F | 3.17 in. |
| December | 23.7 °F | 38.4 °F | 2.74 in. |
| Annual | 41.2 °F | 60.5 °F | 40.73 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 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 |