Mount Vernon, Alabama has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 54.6 °F (low) to 76.7 °F (high). Annual precipitation averages 65.3 Inches. Mount Vernon is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Feb. 21 - Feb. 29 through the first frost around Nov. 21 - Nov. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 35.4 °F | 59.6 °F | 6.1 in. |
| February | 38.9 °F | 63.3 °F | 5.05 in. |
| March | 44.5 °F | 70.4 °F | 5.52 in. |
| April | 51.0 °F | 77.0 °F | 5.01 in. |
| May | 63.5 °F | 84.2 °F | 4.96 in. |
| June | 67.0 °F | 89.5 °F | 6.71 in. |
| July | 73.0 °F | 90.0 °F | 6.89 in. |
| August | 72.6 °F | 89.7 °F | 6.14 in. |
| September | 68.4 °F | 86.1 °F | 5.1 in. |
| October | 57.1 °F | 79.1 °F | 3.68 in. |
| November | 46.3 °F | 69.2 °F | 4.56 in. |
| December | 37.5 °F | 61.8 °F | 5.62 in. |
| Annual | 54.6 °F | 76.7 °F | 65.34 in. |
| Average First Frost Date | Nov. 21 - Nov. 30 |
| Average Last Frost Date | Feb. 21 - Feb. 29 |
| Average Days With Frost | 20-30 Days |
| Plant Hardiness Zone | Zone 8b : 15°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 8a : 10°F to 15°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |