South Mountain, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 55.7 °F (low) to 78.1 °F (high). Annual precipitation averages 34.7 Inches. South Mountain is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Mar. 1 - Mar. 10 through the first frost around Nov. 21 - Nov. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 36.7 °F | 59.7 °F | 2.18 in. |
| February | 40.4 °F | 63.4 °F | 2.48 in. |
| March | 47.4 °F | 70.3 °F | 3.04 in. |
| April | 54.9 °F | 77.9 °F | 2.96 in. |
| May | 63.6 °F | 84.2 °F | 4.3 in. |
| June | 70.7 °F | 91.2 °F | 3.44 in. |
| July | 73.2 °F | 95.2 °F | 1.97 in. |
| August | 73.1 °F | 95.9 °F | 2.53 in. |
| September | 66.8 °F | 89.2 °F | 2.92 in. |
| October | 56.7 °F | 80.1 °F | 3.75 in. |
| November | 46.1 °F | 69.1 °F | 2.63 in. |
| December | 38.6 °F | 61.0 °F | 2.47 in. |
| Annual | 55.7 °F | 78.1 °F | 34.67 in. |
| Average First Frost Date | Nov. 21 - Nov. 30 |
| Average Last Frost Date | Mar. 1 - Mar. 10 |
| Average Days With Frost | 20-30 Days |
| Plant Hardiness Zone | Zone 8b : 15°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 8a : 10°F to 15°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |