Kemah, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 63.8 °F (low) to 77.1 °F (high). Annual precipitation averages 59 Inches. Kemah is located in USDA Plant Hardiness Zone 9b.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 46.9 °F | 61.6 °F | 4.65 in. |
| February | 50.3 °F | 64.7 °F | 3.15 in. |
| March | 56.6 °F | 70.3 °F | 3.38 in. |
| April | 63.2 °F | 76.3 °F | 4.42 in. |
| May | 70.7 °F | 82.7 °F | 5.13 in. |
| June | 76.4 °F | 88.1 °F | 5.98 in. |
| July | 77.9 °F | 90.1 °F | 4.58 in. |
| August | 77.4 °F | 90.8 °F | 6.44 in. |
| September | 74.1 °F | 87.0 °F | 6.3 in. |
| October | 66.6 °F | 79.9 °F | 5.56 in. |
| November | 56.3 °F | 70.6 °F | 4.85 in. |
| December | 48.6 °F | 63.5 °F | 4.55 in. |
| Annual | 63.8 °F | 77.1 °F | 58.99 in. |
| Average First Frost Date | Frost Rare |
| Average Last Frost Date | |
| Average Days With Frost | Frost Rare |
| Plant Hardiness Zone | Zone 9b : 25°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 9a : 20°F to 25°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |