Campbell, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 12.1 °C (low) to 24.1 °C (high). Annual precipitation averages 1140 Millimeters. Campbell 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 | 1.1 °C | 12.7 °C | 74.42 mm |
| February | 3.1 °C | 15.1 °C | 86.11 mm |
| March | 6.9 °C | 19.3 °C | 104.9 mm |
| April | 11.1 °C | 23.6 °C | 105.92 mm |
| May | 16.6 °C | 27.7 °C | 130.81 mm |
| June | 21.1 °C | 32.2 °C | 96.27 mm |
| July | 23 °C | 34.6 °C | 66.8 mm |
| August | 22.5 °C | 35 °C | 65.02 mm |
| September | 18.5 °C | 31.3 °C | 82.55 mm |
| October | 12.3 °C | 25.4 °C | 132.08 mm |
| November | 6.6 °C | 18.8 °C | 97.03 mm |
| December | 2.2 °C | 13.8 °C | 98.04 mm |
| Annual | 12.1 °C | 24.1 °C | 1139.95 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 11 - Mar. 20 |
| Average Days With Frost | 40-50 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 |