Merkel, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 51.9 °F (low) to 76.6 °F (high). Annual precipitation averages 25.4 Inches. Merkel is located in USDA Plant Hardiness Zone 8a. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 31.5 °F | 56.9 °F | 1.06 in. |
| February | 35.0 °F | 60.9 °F | 1.45 in. |
| March | 42.7 °F | 69.0 °F | 1.91 in. |
| April | 50.3 °F | 77.4 °F | 1.84 in. |
| May | 60.4 °F | 84.8 °F | 3.29 in. |
| June | 68.5 °F | 91.4 °F | 3.05 in. |
| July | 71.7 °F | 94.9 °F | 2.11 in. |
| August | 71.2 °F | 94.7 °F | 2.35 in. |
| September | 63.7 °F | 87.1 °F | 3.07 in. |
| October | 53.0 °F | 78.0 °F | 2.52 in. |
| November | 41.5 °F | 66.3 °F | 1.56 in. |
| December | 33.5 °F | 58.0 °F | 1.22 in. |
| Annual | 51.9 °F | 76.6 °F | 25.43 in. |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 8a : 10°F to 15°F |
| Plant Hardiness Zone - 2012 | Zone 8a : 10°F to 15°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |