Millstone, Kentucky has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 44.1 °F (low) to 66.7 °F (high). Annual precipitation averages 49.3 Inches. Millstone 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 | 24.8 °F | 44.9 °F | 3.82 in. |
| February | 27.3 °F | 49.4 °F | 3.84 in. |
| March | 33.4 °F | 58.2 °F | 4.49 in. |
| April | 42.2 °F | 68.8 °F | 4.44 in. |
| May | 51.5 °F | 75.7 °F | 4.83 in. |
| June | 59.8 °F | 81.6 °F | 4.61 in. |
| July | 64.0 °F | 84.0 °F | 5.28 in. |
| August | 63.4 °F | 83.8 °F | 4.23 in. |
| September | 56.7 °F | 79.1 °F | 3.4 in. |
| October | 44.0 °F | 68.5 °F | 2.95 in. |
| November | 33.2 °F | 58.1 °F | 2.99 in. |
| December | 29.0 °F | 48.5 °F | 4.38 in. |
| Annual | 44.1 °F | 66.7 °F | 49.26 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 | Severe Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |