| 2023 Hardiness Zone: | Zone 7b: 5°F to 10°F | |
| 2012 Hardiness Zone: | Zone 6b: -5°F to 0°F Zone 7a: 0°F to 5°F | |
| 1990 Hardiness Zone: | Zone 6b: -5F to 0F | |
| 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: | 64c - Piedmont Uplands | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 31 - 45 days Over 86°F |
Annual Climate Data for ZIP Code 20854 - Potomac, MD | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 24 | 26 | 33 | 42 | 52 | 61 | 65 | 64 | 57 | 44 | 36 | 28 | 44 |
| Avg Max Temp (°F) | 41 | 45 | 54 | 66 | 74 | 82 | 87 | 85 | 78 | 67 | 56 | 46 | 65 |
| Avg Precip (In.) | 3.12 | 2.7 | 3.61 | 3.26 | 4.03 | 3.72 | 3.76 | 3.63 | 4.13 | 3.33 | 3.4 | 3.19 | 41.87 |