Stewartville, Alabama has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 10.5 °C (low) to 23.4 °C (high). Annual precipitation averages 1450.1 Millimeters. Stewartville is located in USDA Plant Hardiness Zone 8a. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 0.7 °C | 12.9 °C | 139.19 mm |
| February | 2.3 °C | 15.4 °C | 143 mm |
| March | 5.6 °C | 19.7 °C | 139.19 mm |
| April | 9.4 °C | 23.7 °C | 125.98 mm |
| May | 14.4 °C | 27.6 °C | 109.73 mm |
| June | 18.8 °C | 30.7 °C | 124.21 mm |
| July | 20.6 °C | 32.3 °C | 122.17 mm |
| August | 20.3 °C | 32 °C | 111.25 mm |
| September | 17 °C | 29.5 °C | 97.28 mm |
| October | 10.6 °C | 24.3 °C | 85.09 mm |
| November | 4.7 °C | 18.7 °C | 115.82 mm |
| December | 2.1 °C | 14.2 °C | 137.16 mm |
| Annual | 10.5 °C | 23.4 °C | 1450.07 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| 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 |