Foristell, Missouri has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 44.8 °F (low) to 65.5 °F (high). Annual precipitation averages 43.1 Inches. Foristell 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 | 21.2 °F | 38.9 °F | 2.41 in. |
| February | 24.6 °F | 44.6 °F | 2.34 in. |
| March | 33.3 °F | 54.9 °F | 3.24 in. |
| April | 44.2 °F | 67.1 °F | 4.58 in. |
| May | 54.5 °F | 75.6 °F | 5.17 in. |
| June | 63.9 °F | 83.9 °F | 4.67 in. |
| July | 67.6 °F | 87.8 °F | 4.16 in. |
| August | 65.6 °F | 86.7 °F | 3.64 in. |
| September | 57.2 °F | 79.9 °F | 3.56 in. |
| October | 45.2 °F | 68.3 °F | 3.38 in. |
| November | 34.6 °F | 54.9 °F | 3.38 in. |
| December | 25.8 °F | 43.1 °F | 2.6 in. |
| Annual | 44.8 °F | 65.5 °F | 43.13 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 | Dfa - Humid Continental Hot Summers With Year Around Precipitation |