Catonsville, Maryland has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 45.7 °F (low) to 65.7 °F (high). Annual precipitation averages 47.9 Inches. Catonsville is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 25.0 °F | 42.5 °F | 3.41 in. |
| February | 26.9 °F | 45.5 °F | 2.97 in. |
| March | 33.4 °F | 54.1 °F | 4.32 in. |
| April | 43.6 °F | 66.1 °F | 3.75 in. |
| May | 52.8 °F | 75.1 °F | 4.4 in. |
| June | 62.0 °F | 83.4 °F | 4.42 in. |
| July | 67.1 °F | 87.6 °F | 4.49 in. |
| August | 65.0 °F | 85.7 °F | 3.92 in. |
| September | 58.4 °F | 79.0 °F | 4.71 in. |
| October | 46.7 °F | 67.4 °F | 4.18 in. |
| November | 37.2 °F | 56.2 °F | 3.35 in. |
| December | 29.9 °F | 46.3 °F | 3.98 in. |
| Annual | 45.7 °F | 65.7 °F | 47.9 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7b : 5°F to 10°F |
| Plant Hardiness Zone - 2012 | Zone 7a : 0°F to 5°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |