| 2023 Hardiness Zone: | Zone 8a: 10°F to 15°F Zone 7b: 5°F to 10°F | |
| 2012 Hardiness Zone: | Zone 7b: 5°F to 10°F Zone 7a: 0°F to 5°F | |
| 1990 Hardiness Zone: | Zone 7a: 0F to 5F | |
| Average First Frost Date: | Oct. 21 - Oct. 31 | |
| Average Last Frost Date: | Apr. 21 - Apr. 30 | |
| Koppen-Geiger Climate Zone: | Cfa - Humid Subtropical Climate | |
| Ecoregion: | 65n - Chesapeake Rolling Coastal Plain | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 15 - 30 days Over 86°F |
Annual Climate Data for ZIP Code 20659 - Mechanicsville, MD | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 26 | 28 | 35 | 43 | 53 | 62 | 66 | 65 | 59 | 47 | 38 | 30 | 46 |
| Avg Max Temp (°F) | 45 | 48 | 57 | 67 | 75 | 83 | 87 | 85 | 79 | 68 | 59 | 49 | 67 |
| Avg Precip (In.) | 3.85 | 3.24 | 4.43 | 3.39 | 4.24 | 4.1 | 4.38 | 3.94 | 4.28 | 3.72 | 3.4 | 3.34 | 46.32 |