Seymour, Missouri has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 46.2 °F (low) to 65.7 °F (high). Annual precipitation averages 47.7 Inches. Seymour is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 23.0 °F | 41.6 °F | 2.77 in. |
| February | 26.8 °F | 46.2 °F | 2.85 in. |
| March | 35.5 °F | 55.6 °F | 4.24 in. |
| April | 45.2 °F | 65.9 °F | 5.06 in. |
| May | 54.9 °F | 74.6 °F | 5.75 in. |
| June | 63.9 °F | 82.6 °F | 4.4 in. |
| July | 68.0 °F | 87.2 °F | 4.32 in. |
| August | 66.2 °F | 86.5 °F | 3.5 in. |
| September | 58.7 °F | 79.6 °F | 4.2 in. |
| October | 47.3 °F | 68.1 °F | 3.64 in. |
| November | 37.1 °F | 55.7 °F | 4.06 in. |
| December | 27.4 °F | 44.4 °F | 2.93 in. |
| Annual | 46.2 °F | 65.7 °F | 47.72 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |