| 2023 Hardiness Zone: | Zone 7b: 5°F to 10°F Zone 7a: 0°F to 5°F | |
| 2012 Hardiness Zone: | Zone 6b: -5°F to 0°F Zone 7a: 0°F to 5°F | |
| 1990 Hardiness Zone: | Zone 7a: 0F to 5F | |
| Average First Frost Date: | Oct. 11 - Oct. 20 | |
| Average Last Frost Date: | Apr. 21 - Apr. 30 | |
| Koppen-Geiger Climate Zone: | Dfa - Humid Continental Hot Summers | |
| Ecoregion: | 64a - Triassic Lowlands | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 15 - 30 days Over 86°F |
Annual Climate Data for ZIP Code 20837 - Poolesville, MD | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 23 | 25 | 33 | 42 | 51 | 60 | 65 | 63 | 56 | 43 | 35 | 27 | 44 |
| Avg Max Temp (°F) | 42 | 46 | 55 | 66 | 75 | 83 | 87 | 86 | 79 | 68 | 57 | 46 | 66 |
| Avg Precip (In.) | 3.16 | 2.7 | 3.65 | 3.22 | 4.3 | 3.84 | 3.76 | 3.59 | 4.06 | 3.34 | 3.31 | 3.1 | 42.04 |