Hayneville, Alabama has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 12 °C (low) to 24.6 °C (high). Annual precipitation averages 1345.7 Millimeters. Hayneville is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Mar. 1 - Mar. 10 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 2 °C | 14.3 °C | 127.25 mm |
| February | 3.9 °C | 16.8 °C | 122.43 mm |
| March | 7.3 °C | 20.9 °C | 137.67 mm |
| April | 11.2 °C | 24.9 °C | 109.22 mm |
| May | 16 °C | 28.9 °C | 93.47 mm |
| June | 20.3 °C | 31.9 °C | 105.66 mm |
| July | 21.9 °C | 33.3 °C | 126.49 mm |
| August | 21.6 °C | 33.1 °C | 110.24 mm |
| September | 18.7 °C | 30.7 °C | 108.46 mm |
| October | 12.1 °C | 25.5 °C | 80.52 mm |
| November | 5.9 °C | 19.9 °C | 106.68 mm |
| December | 3.3 °C | 15.4 °C | 117.6 mm |
| Annual | 12 °C | 24.6 °C | 1345.69 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 1 - Mar. 10 |
| Average Days With Frost | 30-40 Days |
| Plant Hardiness Zone | Zone 8b : -9.4°C to -6.7°C |
| Plant Hardiness Zone - 2012 | Zone 8a : -12.2°C to -9.4°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |