Hillsboro, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 55.1 °F (low) to 77.3 °F (high). Annual precipitation averages 38.7 Inches. Hillsboro 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 | 35.4 °F | 57.8 °F | 2.76 in. |
| February | 39.2 °F | 61.8 °F | 2.76 in. |
| March | 46.5 °F | 68.8 °F | 3.58 in. |
| April | 53.7 °F | 76.2 °F | 3.57 in. |
| May | 63.1 °F | 83.6 °F | 4.55 in. |
| June | 70.6 °F | 91.2 °F | 3.88 in. |
| July | 73.7 °F | 95.5 °F | 1.71 in. |
| August | 73.5 °F | 96.3 °F | 2.3 in. |
| September | 66.7 °F | 89.9 °F | 3.08 in. |
| October | 55.8 °F | 79.8 °F | 4.68 in. |
| November | 45.5 °F | 67.8 °F | 2.81 in. |
| December | 37.4 °F | 59.4 °F | 2.99 in. |
| Annual | 55.1 °F | 77.3 °F | 38.67 in. |
| 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 : 15°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 8a : 10°F to 15°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |