New Castle, Kentucky has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 44.3 °F (low) to 65.2 °F (high). Annual precipitation averages 49.7 Inches. New Castle is located in USDA Plant Hardiness Zone 6b. 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 | 23.0 °F | 40.6 °F | 3.6 in. |
| February | 25.6 °F | 44.9 °F | 3.57 in. |
| March | 33.0 °F | 54.5 °F | 4.47 in. |
| April | 43.3 °F | 65.6 °F | 4.87 in. |
| May | 53.9 °F | 74.3 °F | 5.41 in. |
| June | 61.2 °F | 83.6 °F | 4.96 in. |
| July | 65.0 °F | 86.4 °F | 4.45 in. |
| August | 63.6 °F | 84.7 °F | 3.63 in. |
| September | 56.6 °F | 79.3 °F | 3.63 in. |
| October | 44.5 °F | 68.7 °F | 3.53 in. |
| November | 34.3 °F | 55.1 °F | 3.5 in. |
| December | 27.5 °F | 44.5 °F | 4.05 in. |
| Annual | 44.3 °F | 65.2 °F | 49.67 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 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |