County Line, Alabama has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 9.8 °C (low) to 23.1 °C (high). Annual precipitation averages 1483.9 Millimeters. County Line is located in USDA Plant Hardiness Zone 8a. 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 | -0.4 °C | 12 °C | 136.65 mm |
| February | 1 °C | 14.3 °C | 132.84 mm |
| March | 4.8 °C | 19 °C | 143.51 mm |
| April | 8.7 °C | 23.7 °C | 140.72 mm |
| May | 13.9 °C | 27.4 °C | 121.67 mm |
| June | 18.4 °C | 30.9 °C | 103.38 mm |
| July | 20.3 °C | 32.6 °C | 119.89 mm |
| August | 19.9 °C | 32.4 °C | 109.73 mm |
| September | 16.6 °C | 29.8 °C | 113.28 mm |
| October | 9.6 °C | 24.2 °C | 87.63 mm |
| November | 3.8 °C | 18.1 °C | 116.59 mm |
| December | 1.3 °C | 13.3 °C | 157.99 mm |
| Annual | 9.8 °C | 23.1 °C | 1483.88 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 8a : -12.2°C to -9.4°C |
| Plant Hardiness Zone - 2012 | Zone 7b : -15°C to -12.2°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |