| 2023 Hardiness Zone: | Zone 8b: 15°F to 20°F Zone 9a: 20°F to 25°F |
| 2012 Hardiness Zone: | Zone 8b: 15°F to 20°F |
| 1990 Hardiness Zone: | Zone 8a: 10F to 15F |
| Average First Frost Date: | Nov. 21 - Nov. 30 |
| Average Last Frost Date: | Mar. 1 - Mar. 10 |
| Koppen-Geiger Climate Zone: | Cfa - Humid Subtropical Climate |
| Ecoregion: | 33b - Southern Post Oak Savanna |
| Heat Zone Days: | 121 - 150 days Over 86°F |
Annual Climate Data for ZIP Code 77837 - Calvert, TX | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 38 | 42 | 49 | 56 | 64 | 70 | 73 | 72 | 67 | 57 | 48 | 40 | 56 |
| Avg Max Temp (°F) | 60 | 65 | 73 | 79 | 85 | 91 | 95 | 96 | 90 | 81 | 70 | 62 | 79 |
| Avg Precip (In.) | 2.74 | 2.69 | 2.88 | 3.13 | 4.87 | 3.25 | 2.03 | 2.31 | 3.52 | 4.24 | 3.25 | 3.22 | 38.13 |