Smithville, Tennessee has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 45.8 °F (low) to 68.9 °F (high). Annual precipitation averages 56.9 Inches. Smithville is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 26.7 °F | 47.0 °F | 4.95 in. |
| February | 29.2 °F | 51.4 °F | 4.77 in. |
| March | 35.7 °F | 59.8 °F | 5.61 in. |
| April | 43.7 °F | 69.8 °F | 5.02 in. |
| May | 53.8 °F | 77.5 °F | 5.02 in. |
| June | 62.3 °F | 84.3 °F | 5.31 in. |
| July | 66.3 °F | 87.2 °F | 5.08 in. |
| August | 64.6 °F | 86.7 °F | 3.89 in. |
| September | 57.5 °F | 81.3 °F | 3.9 in. |
| October | 45.1 °F | 71.4 °F | 3.33 in. |
| November | 34.7 °F | 59.9 °F | 4.04 in. |
| December | 29.8 °F | 50.8 °F | 5.96 in. |
| Annual | 45.8 °F | 68.9 °F | 56.88 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7a : 0°F to 5°F |
| Plant Hardiness Zone - 2012 | Zone 7a : 0°F to 5°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |