Hamlin, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 10.6 °C (low) to 25.1 °C (high). Annual precipitation averages 604.5 Millimeters. Hamlin 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 | -1 °C | 13.7 °C | 26.42 mm |
| February | 0.8 °C | 15.9 °C | 30.23 mm |
| March | 5.2 °C | 20.7 °C | 39.62 mm |
| April | 9.6 °C | 25.7 °C | 49.02 mm |
| May | 15.3 °C | 29.8 °C | 82.3 mm |
| June | 20.1 °C | 33.7 °C | 78.49 mm |
| July | 22.1 °C | 35.8 °C | 44.7 mm |
| August | 21.6 °C | 35.5 °C | 55.12 mm |
| September | 17.3 °C | 31.1 °C | 78.23 mm |
| October | 11.1 °C | 25.8 °C | 52.83 mm |
| November | 4.6 °C | 19.1 °C | 36.58 mm |
| December | 0.1 °C | 14.3 °C | 30.99 mm |
| Annual | 10.6 °C | 25.1 °C | 604.53 mm |
| 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 : -12.2°C to -9.4°C |
| Plant Hardiness Zone - 2012 | Zone 7b : -15°C to -12.2°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |