Castalian Springs, Tennessee has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 46.9 °F (low) to 69.4 °F (high). Annual precipitation averages 54 Inches. Castalian Springs is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 27.1 °F | 46.6 °F | 4.31 in. |
| February | 29.6 °F | 51.3 °F | 4.73 in. |
| March | 36.5 °F | 60.2 °F | 4.92 in. |
| April | 45.0 °F | 70.0 °F | 4.93 in. |
| May | 55.0 °F | 78.0 °F | 5.49 in. |
| June | 63.7 °F | 85.4 °F | 4.43 in. |
| July | 67.6 °F | 88.6 °F | 4.86 in. |
| August | 66.6 °F | 88.1 °F | 3.98 in. |
| September | 58.9 °F | 82.6 °F | 3.86 in. |
| October | 46.5 °F | 71.9 °F | 3.67 in. |
| November | 36.0 °F | 59.5 °F | 3.86 in. |
| December | 30.8 °F | 50.1 °F | 4.98 in. |
| Annual | 46.9 °F | 69.4 °F | 54.02 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7b : 5°F to 10°F |
| Plant Hardiness Zone - 2012 | Zone 7a : 0°F to 5°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |