Zena, Oklahoma has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 8.7 °C (low) to 21.3 °C (high). Annual precipitation averages 1212.3 Millimeters. Zena is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -3.4 °C | 8.6 °C | 64.77 mm |
| February | -1.5 °C | 11.2 °C | 59.44 mm |
| March | 3.2 °C | 16.3 °C | 99.31 mm |
| April | 8 °C | 21.4 °C | 122.94 mm |
| May | 13.4 °C | 25.4 °C | 162.81 mm |
| June | 18.4 °C | 29.9 °C | 123.44 mm |
| July | 20.7 °C | 32.9 °C | 104.9 mm |
| August | 19.7 °C | 32.8 °C | 92.46 mm |
| September | 15.3 °C | 28.6 °C | 115.57 mm |
| October | 8.9 °C | 22.4 °C | 106.93 mm |
| November | 3.2 °C | 15.8 °C | 87.88 mm |
| December | -1.6 °C | 10.1 °C | 71.88 mm |
| Annual | 8.7 °C | 21.3 °C | 1212.33 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |