South Williamson, Kentucky has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 45.4 °F (low) to 69.1 °F (high). Annual precipitation averages 48.6 Inches. South Williamson 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 | 25.5 °F | 45.7 °F | 3.59 in. |
| February | 28.0 °F | 49.8 °F | 3.54 in. |
| March | 34.1 °F | 58.8 °F | 4.51 in. |
| April | 43.7 °F | 71.6 °F | 4.02 in. |
| May | 53.4 °F | 78.9 °F | 4.66 in. |
| June | 61.8 °F | 85.4 °F | 4.9 in. |
| July | 65.8 °F | 88.7 °F | 5.6 in. |
| August | 64.9 °F | 87.9 °F | 3.96 in. |
| September | 57.8 °F | 82.5 °F | 3.35 in. |
| October | 45.4 °F | 71.2 °F | 3.08 in. |
| November | 34.6 °F | 59.0 °F | 3.05 in. |
| December | 29.3 °F | 49.4 °F | 4.31 in. |
| Annual | 45.4 °F | 69.1 °F | 48.57 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 6b : -5°F to 0°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |