Mountain Brook, Alabama has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 53.4 °F (low) to 73.1 °F (high). Annual precipitation averages 59.1 Inches. Mountain Brook is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 35.0 °F | 53.6 °F | 5.22 in. |
| February | 37.4 °F | 58.0 °F | 5.54 in. |
| March | 44.4 °F | 66.1 °F | 5.62 in. |
| April | 51.8 °F | 73.8 °F | 5.24 in. |
| May | 60.9 °F | 80.7 °F | 4.55 in. |
| June | 68.7 °F | 86.7 °F | 4.99 in. |
| July | 71.7 °F | 89.8 °F | 5.09 in. |
| August | 71.1 °F | 89.2 °F | 4.49 in. |
| September | 65.5 °F | 84.8 °F | 4.53 in. |
| October | 54.0 °F | 74.6 °F | 3.44 in. |
| November | 43.3 °F | 64.1 °F | 4.84 in. |
| December | 37.4 °F | 55.9 °F | 5.57 in. |
| Annual | 53.4 °F | 73.1 °F | 59.12 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 40-50 Days |
| Plant Hardiness Zone | Zone 8b : 15°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 8a : 10°F to 15°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |