Seymour, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 50.9 °F (low) to 76.5 °F (high). Annual precipitation averages 27.7 Inches. Seymour is located in USDA Plant Hardiness Zone 8a. 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 | 29.4 °F | 55.4 °F | 1.19 in. |
| February | 32.4 °F | 59.2 °F | 1.55 in. |
| March | 40.8 °F | 67.9 °F | 2.1 in. |
| April | 48.7 °F | 76.4 °F | 1.89 in. |
| May | 59.5 °F | 84.4 °F | 3.7 in. |
| June | 68.6 °F | 92.0 °F | 3.33 in. |
| July | 72.5 °F | 97.0 °F | 2.35 in. |
| August | 71.5 °F | 96.7 °F | 2.55 in. |
| September | 63.7 °F | 88.2 °F | 3.06 in. |
| October | 52.2 °F | 78.0 °F | 2.73 in. |
| November | 40.2 °F | 65.9 °F | 1.94 in. |
| December | 31.6 °F | 56.6 °F | 1.31 in. |
| Annual | 50.9 °F | 76.5 °F | 27.7 in. |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 11 - Mar. 20 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 8a : 10°F to 15°F |
| Plant Hardiness Zone - 2012 | Zone 7b : 5°F to 10°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |