Round Top, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 57.9 °F (low) to 79.4 °F (high). Annual precipitation averages 41.3 Inches. Round Top is located in USDA Plant Hardiness Zone 9a. 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 | 40.6 °F | 61.5 °F | 3.29 in. |
| February | 44.0 °F | 64.8 °F | 3.03 in. |
| March | 50.7 °F | 71.8 °F | 3.2 in. |
| April | 57.2 °F | 79.1 °F | 3.18 in. |
| May | 65.5 °F | 85.7 °F | 4.62 in. |
| June | 71.8 °F | 91.8 °F | 4.04 in. |
| July | 73.6 °F | 94.7 °F | 1.81 in. |
| August | 73.6 °F | 96.8 °F | 3.36 in. |
| September | 68.5 °F | 90.6 °F | 3.33 in. |
| October | 58.7 °F | 81.7 °F | 4.51 in. |
| November | 48.9 °F | 70.8 °F | 3.49 in. |
| December | 42.1 °F | 63.2 °F | 3.4 in. |
| Annual | 57.9 °F | 79.4 °F | 41.26 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 9a : 20°F to 25°F |
| Plant Hardiness Zone - 2012 | Zone 8b : 15°F to 20°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |