Crystal City, Missouri has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 47.3 °F (low) to 67 °F (high). Annual precipitation averages 43.5 Inches. Crystal City 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 | 23.8 °F | 40.7 °F | 2.74 in. |
| February | 27.5 °F | 46.2 °F | 2.47 in. |
| March | 36.0 °F | 56.0 °F | 3.94 in. |
| April | 46.5 °F | 68.0 °F | 5.01 in. |
| May | 57.0 °F | 77.2 °F | 4.77 in. |
| June | 65.7 °F | 85.9 °F | 4.29 in. |
| July | 69.8 °F | 89.4 °F | 4.04 in. |
| August | 67.7 °F | 87.9 °F | 3.53 in. |
| September | 59.8 °F | 81.4 °F | 3.4 in. |
| October | 48.0 °F | 69.9 °F | 2.99 in. |
| November | 37.2 °F | 56.2 °F | 3.42 in. |
| December | 28.2 °F | 45.0 °F | 2.86 in. |
| Annual | 47.3 °F | 67 °F | 43.46 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 |