Tomball, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 59.1 °F (low) to 79.3 °F (high). Annual precipitation averages 50.9 Inches. Tomball is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Feb. 1 - Feb. 10 through the first frost around Dec. 21 - Dec. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 42.1 °F | 62.5 °F | 3.93 in. |
| February | 45.8 °F | 66.0 °F | 3.34 in. |
| March | 52.1 °F | 72.5 °F | 3.45 in. |
| April | 58.7 °F | 78.8 °F | 3.71 in. |
| May | 66.8 °F | 85.5 °F | 5.16 in. |
| June | 72.6 °F | 91.1 °F | 5.05 in. |
| July | 74.4 °F | 93.3 °F | 3.76 in. |
| August | 74.0 °F | 94.3 °F | 4.75 in. |
| September | 69.3 °F | 89.7 °F | 4.53 in. |
| October | 59.8 °F | 81.9 °F | 4.79 in. |
| November | 50.2 °F | 71.7 °F | 4.48 in. |
| December | 43.6 °F | 64.1 °F | 3.98 in. |
| Annual | 59.1 °F | 79.3 °F | 50.93 in. |
| Average First Frost Date | Dec. 21 - Dec. 31 |
| Average Last Frost Date | Feb. 1 - Feb. 10 |
| Average Days With Frost | 10-20 Days |
| Plant Hardiness Zone | Zone 9a : 20°F to 25°F |
| Plant Hardiness Zone - 2012 | Zone 9a : 20°F to 25°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |