Smithville, Mississippi has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 10.6 °C (low) to 23.4 °C (high). Annual precipitation averages 1459 Millimeters. Smithville 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 | -0.1 °C | 11.5 °C | 133.1 mm |
| February | 1.7 °C | 14.2 °C | 135.64 mm |
| March | 5.6 °C | 19.1 °C | 130.81 mm |
| April | 10.1 °C | 23.7 °C | 140.21 mm |
| May | 15.1 °C | 28 °C | 132.59 mm |
| June | 19.6 °C | 31.8 °C | 117.86 mm |
| July | 21.5 °C | 33.2 °C | 114.05 mm |
| August | 20.8 °C | 33.3 °C | 100.33 mm |
| September | 17 °C | 30.3 °C | 97.79 mm |
| October | 10.2 °C | 24.7 °C | 93.73 mm |
| November | 4.3 °C | 17.9 °C | 112.27 mm |
| December | 1.5 °C | 13 °C | 150.62 mm |
| Annual | 10.6 °C | 23.4 °C | 1459 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 |