Hamilton, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 12.1 °C (low) to 25.2 °C (high). Annual precipitation averages 837.7 Millimeters. Hamilton is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Mar. 11 - Mar. 20 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 1.5 °C | 14.7 °C | 53.59 mm |
| February | 3.3 °C | 16.8 °C | 55.12 mm |
| March | 7.3 °C | 20.7 °C | 76.2 mm |
| April | 11.5 °C | 25.1 °C | 72.14 mm |
| May | 16.6 °C | 28.8 °C | 98.3 mm |
| June | 20.6 °C | 32.7 °C | 100.84 mm |
| July | 22.2 °C | 35 °C | 52.07 mm |
| August | 21.9 °C | 35.4 °C | 56.13 mm |
| September | 18.3 °C | 31.6 °C | 74.17 mm |
| October | 12.5 °C | 26.3 °C | 89.41 mm |
| November | 6.7 °C | 20 °C | 58.42 mm |
| December | 2.4 °C | 15.4 °C | 51.31 mm |
| Annual | 12.1 °C | 25.2 °C | 837.7 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 11 - Mar. 20 |
| Average Days With Frost | 30-40 Days |
| Plant Hardiness Zone | Zone 8b : -9.4°C to -6.7°C |
| Plant Hardiness Zone - 2012 | Zone 8a : -12.2°C to -9.4°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |