| 2023 Hardiness Zone: | 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: | Nov. 1 - Nov. 10 | |
| Average Last Frost Date: | Apr. 11 - Apr. 20 | |
| 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 20622 - Charlotte Hall, MD | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 26 | 28 | 35 | 43 | 53 | 62 | 67 | 65 | 59 | 47 | 38 | 30 | 46 |
| Avg Max Temp (°F) | 45 | 48 | 58 | 68 | 76 | 83 | 87 | 85 | 79 | 69 | 59 | 49 | 67 |
| Avg Precip (In.) | 3.76 | 3.15 | 4.3 | 3.33 | 4.22 | 3.99 | 4.34 | 3.96 | 4.23 | 3.64 | 3.36 | 3.32 | 45.6 |