Signal Mountain, Tennessee has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 48 °F (low) to 66.6 °F (high). Annual precipitation averages 67.8 Inches. Signal Mountain is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 28.5 °F | 45.1 °F | 6.35 in. |
| February | 31.6 °F | 49.5 °F | 5.95 in. |
| March | 38.7 °F | 58.1 °F | 6.38 in. |
| April | 47.4 °F | 68.0 °F | 5.67 in. |
| May | 55.7 °F | 75.3 °F | 5.2 in. |
| June | 63.0 °F | 81.7 °F | 5.47 in. |
| July | 66.2 °F | 84.8 °F | 5.6 in. |
| August | 65.4 °F | 84.2 °F | 4.36 in. |
| September | 59.6 °F | 79.0 °F | 5.37 in. |
| October | 48.6 °F | 68.6 °F | 4.14 in. |
| November | 39.2 °F | 56.9 °F | 5.92 in. |
| December | 32.6 °F | 47.9 °F | 7.37 in. |
| Annual | 48 °F | 66.6 °F | 67.78 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 50-75 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 |