| 2023 Hardiness Zone: | Zone 9a: 20°F to 25°F | |
| 2012 Hardiness Zone: | Zone 9a: 20°F to 25°F | |
| 1990 Hardiness Zone: | Zone 8b: 15F to 20F | |
| Average First Frost Date: | Dec. 11 - Dec. 20 | |
| Average Last Frost Date: | Feb. 11 - Feb. 20 | |
| Koppen-Geiger Climate Zone: | Cfa - Humid Subtropical Climate | |
| Ecoregion: | 32b - Southern Blackland/Fayette Prairie | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 121 - 150 days Over 86°F |
Annual Climate Data for ZIP Code 77964 - Hallettsville, TX | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 42 | 45 | 52 | 58 | 66 | 72 | 73 | 73 | 69 | 60 | 51 | 44 | 59 |
| Avg Max Temp (°F) | 64 | 68 | 74 | 80 | 86 | 91 | 94 | 95 | 90 | 83 | 73 | 65 | 80 |
| Avg Precip (In.) | 2.91 | 2.46 | 2.48 | 3.37 | 5.61 | 4.84 | 2.26 | 2.9 | 4.4 | 4.03 | 3.5 | 2.76 | 41.52 |