| 2023 Hardiness Zone: | Zone 8a: 10°F to 15°F |
| 2012 Hardiness Zone: | Zone 8a: 10°F to 15°F Zone 7b: 5°F to 10°F |
| 1990 Hardiness Zone: | Zone 7b: 5F to 10F |
| Average First Frost Date: | Nov. 11 - Nov. 20 |
| Average Last Frost Date: | Apr. 1 - Apr. 10 |
| Koppen-Geiger Climate Zone: | Cfa - Humid Subtropical Climate |
| Ecoregion: | 27h - Red Prairie |
| Heat Zone Days: | 121 - 150 days Over 86°F |
Annual Climate Data for ZIP Code 79536 - Merkel, TX | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 30 | 34 | 41 | 50 | 59 | 67 | 71 | 70 | 63 | 52 | 40 | 32 | 51 |
| Avg Max Temp (°F) | 56 | 61 | 70 | 78 | 86 | 92 | 95 | 94 | 87 | 78 | 65 | 57 | 77 |
| Avg Precip (In.) | .94 | 1.27 | 1.22 | 1.82 | 2.93 | 2.82 | 2.11 | 2.68 | 3.24 | 2.54 | 1.22 | 1.17 | 23.94 |