Heavener, Oklahoma has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 9.7 °C (low) to 23 °C (high). Annual precipitation averages 1324.6 Millimeters. Heavener 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 | -2.1 °C | 10.9 °C | 75.18 mm |
| February | 0.1 °C | 13.5 °C | 75.69 mm |
| March | 4.4 °C | 18.1 °C | 102.11 mm |
| April | 9 °C | 22.7 °C | 137.41 mm |
| May | 14.4 °C | 26.6 °C | 184.4 mm |
| June | 19.2 °C | 31.3 °C | 113.03 mm |
| July | 21.3 °C | 34.2 °C | 82.8 mm |
| August | 20.4 °C | 34.1 °C | 107.95 mm |
| September | 16.2 °C | 30.2 °C | 116.59 mm |
| October | 9.6 °C | 24.2 °C | 113.03 mm |
| November | 4 °C | 17.7 °C | 120.65 mm |
| December | -0.6 °C | 12.2 °C | 95.76 mm |
| Annual | 9.7 °C | 23 °C | 1324.6 mm |
| 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 : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7b : -15°C to -12.2°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |