Smithville, Georgia has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 12.5 °C (low) to 24.8 °C (high). Annual precipitation averages 1281.7 Millimeters. Smithville is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Mar. 11 - Mar. 20 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 2.7 °C | 15.1 °C | 120.9 mm |
| February | 4.3 °C | 17.1 °C | 111.76 mm |
| March | 7.6 °C | 21.1 °C | 122.94 mm |
| April | 11.6 °C | 25 °C | 103.12 mm |
| May | 16.7 °C | 29.2 °C | 75.44 mm |
| June | 20.7 °C | 31.9 °C | 121.41 mm |
| July | 22.1 °C | 33.1 °C | 130.05 mm |
| August | 21.8 °C | 32.6 °C | 115.57 mm |
| September | 18.9 °C | 30.3 °C | 102.36 mm |
| October | 12.9 °C | 25.8 °C | 68.58 mm |
| November | 7 °C | 20.4 °C | 84.33 mm |
| December | 4.2 °C | 16.3 °C | 125.22 mm |
| Annual | 12.5 °C | 24.8 °C | 1281.68 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 11 - Mar. 20 |
| Average Days With Frost | 30-40 Days |
| Plant Hardiness Zone | Zone 8b : -9.4°C to -6.7°C |
| Plant Hardiness Zone - 2012 | Zone 8b : -9.4°C to -6.7°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |