Marietta, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 52.9 °F (low) to 75.7 °F (high). Annual precipitation averages 50.8 Inches. Marietta is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Mar. 1 - Mar. 10 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 33.9 °F | 55.8 °F | 3.74 in. |
| February | 36.8 °F | 59.6 °F | 4.45 in. |
| March | 44.3 °F | 67.6 °F | 4.73 in. |
| April | 51.6 °F | 75.3 °F | 4.52 in. |
| May | 61.2 °F | 82.6 °F | 5.1 in. |
| June | 68.8 °F | 89.5 °F | 4.18 in. |
| July | 71.8 °F | 93.5 °F | 3.53 in. |
| August | 70.8 °F | 94.1 °F | 2.87 in. |
| September | 64.5 °F | 88.1 °F | 4.14 in. |
| October | 52.3 °F | 77.8 °F | 4.8 in. |
| November | 42.9 °F | 66.3 °F | 4.03 in. |
| December | 35.8 °F | 57.7 °F | 4.7 in. |
| Annual | 52.9 °F | 75.7 °F | 50.79 in. |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 1 - Mar. 10 |
| Average Days With Frost | 40-50 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 | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |