Walnut Grove, Alabama has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 10.2 °C (low) to 21.6 °C (high). Annual precipitation averages 1463.1 Millimeters. Walnut Grove 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 | -0.2 °C | 10.2 °C | 137.67 mm |
| February | 1.3 °C | 12.6 °C | 131.57 mm |
| March | 5.1 °C | 17.2 °C | 145.54 mm |
| April | 9.3 °C | 21.9 °C | 138.43 mm |
| May | 14.4 °C | 26.1 °C | 118.87 mm |
| June | 18.7 °C | 29.8 °C | 132.59 mm |
| July | 20.6 °C | 31.3 °C | 114.81 mm |
| August | 20.1 °C | 31.1 °C | 108.2 mm |
| September | 16.7 °C | 28.4 °C | 102.62 mm |
| October | 10.2 °C | 22.8 °C | 81.03 mm |
| November | 4.3 °C | 16.3 °C | 108.97 mm |
| December | 1.3 °C | 11.8 °C | 142.75 mm |
| Annual | 10.2 °C | 21.6 °C | 1463.05 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 |