| 2023 Hardiness Zone: | Zone 7b: 5°F to 10°F | |
| 2012 Hardiness Zone: | Zone 7a: 0°F to 5°F | |
| 1990 Hardiness Zone: | Zone 6b: -5F to 0F | |
| Average First Frost Date: | Oct. 21 - Oct. 31 | |
| 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: | 46 - 60 days Over 86°F |
Annual Climate Data for ZIP Code 20816 - Bethesda, MD | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 24 | 26 | 33 | 42 | 52 | 61 | 66 | 65 | 58 | 45 | 36 | 28 | 45 |
| Avg Max Temp (°F) | 43 | 47 | 56 | 67 | 76 | 84 | 88 | 86 | 79 | 69 | 57 | 47 | 67 |
| Avg Precip (In.) | 3.39 | 2.91 | 3.97 | 3.41 | 4.37 | 3.71 | 4.12 | 3.92 | 4.21 | 3.47 | 3.41 | 3.32 | 44.21 |