Webster Groves, Missouri has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 47.5 °F (low) to 66.6 °F (high). Annual precipitation averages 44.9 Inches. Webster Groves 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 | 40.3 °F | 2.77 in. |
| February | 27.2 °F | 45.8 °F | 2.49 in. |
| March | 35.9 °F | 56.0 °F | 3.61 in. |
| April | 46.7 °F | 68.0 °F | 4.71 in. |
| May | 57.3 °F | 76.9 °F | 5.31 in. |
| June | 66.4 °F | 85.4 °F | 4.64 in. |
| July | 70.2 °F | 89.0 °F | 4.15 in. |
| August | 68.3 °F | 87.7 °F | 3.8 in. |
| September | 60.1 °F | 81.1 °F | 3.38 in. |
| October | 48.6 °F | 69.4 °F | 3.56 in. |
| November | 37.1 °F | 55.4 °F | 3.71 in. |
| December | 28.5 °F | 44.7 °F | 2.78 in. |
| Annual | 47.5 °F | 66.6 °F | 44.91 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 |