Union City, Oklahoma has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 48.7 °F (low) to 71.7 °F (high). Annual precipitation averages 34.2 Inches. Union City is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 26.7 °F | 49.3 °F | 1.21 in. |
| February | 29.8 °F | 53.2 °F | 1.46 in. |
| March | 38.3 °F | 62.6 °F | 2.47 in. |
| April | 46.6 °F | 70.9 °F | 3.38 in. |
| May | 57.5 °F | 79.3 °F | 5.35 in. |
| June | 66.8 °F | 88.4 °F | 4.5 in. |
| July | 70.9 °F | 93.8 °F | 3.07 in. |
| August | 69.5 °F | 93.1 °F | 3.26 in. |
| September | 61.6 °F | 85.1 °F | 3.02 in. |
| October | 49.4 °F | 73.5 °F | 3.02 in. |
| November | 37.8 °F | 61.1 °F | 1.8 in. |
| December | 28.9 °F | 50.4 °F | 1.67 in. |
| Annual | 48.7 °F | 71.7 °F | 34.21 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 7b : 5°F to 10°F |
| Plant Hardiness Zone - 2012 | Zone 7a : 0°F to 5°F |
| Current Drought Conditions | Extreme Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |