Festus, Missouri has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 46.9 °F (low) to 66.9 °F (high). Annual precipitation averages 43.5 Inches. Festus is located in USDA Plant Hardiness Zone 7a. 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 | 23.5 °F | 40.8 °F | 2.74 in. |
| February | 27.2 °F | 46.2 °F | 2.47 in. |
| March | 35.6 °F | 56.0 °F | 3.94 in. |
| April | 46.1 °F | 67.9 °F | 5.02 in. |
| May | 56.6 °F | 77.0 °F | 4.79 in. |
| June | 65.4 °F | 85.7 °F | 4.28 in. |
| July | 69.4 °F | 89.1 °F | 4.03 in. |
| August | 67.4 °F | 87.7 °F | 3.55 in. |
| September | 59.4 °F | 81.3 °F | 3.41 in. |
| October | 47.5 °F | 69.8 °F | 3.0 in. |
| November | 36.9 °F | 56.1 °F | 3.42 in. |
| December | 28.1 °F | 44.9 °F | 2.86 in. |
| Annual | 46.9 °F | 66.9 °F | 43.51 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 7a : 0°F to 5°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |