Henagar, Alabama has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 8.5 °C (low) to 20.5 °C (high). Annual precipitation averages 1482.1 Millimeters. Henagar is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -2.1 °C | 9.2 °C | 147.83 mm |
| February | 0.2 °C | 11.4 °C | 143.26 mm |
| March | 3.3 °C | 16.1 °C | 140.72 mm |
| April | 7.6 °C | 20.7 °C | 131.83 mm |
| May | 12.4 °C | 24.8 °C | 115.57 mm |
| June | 17.2 °C | 28.7 °C | 116.33 mm |
| July | 18.6 °C | 30.1 °C | 116.08 mm |
| August | 18.2 °C | 29.9 °C | 90.68 mm |
| September | 14.9 °C | 27.2 °C | 112.52 mm |
| October | 8.6 °C | 21.8 °C | 88.14 mm |
| November | 2.8 °C | 15.6 °C | 125.22 mm |
| December | 0.3 °C | 10.8 °C | 153.92 mm |
| Annual | 8.5 °C | 20.5 °C | 1482.1 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7b : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |