| 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 6a: -10F to -5F | |
| Average First Frost Date: | Oct. 21 - Oct. 31 | |
| 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: | 8 - 14 days Over 86°F |
Annual Climate Data for ZIP Code 21788 - Thurmont, MD | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 22 | 24 | 32 | 41 | 51 | 59 | 64 | 63 | 56 | 44 | 35 | 27 | 43 |
| Avg Max Temp (°F) | 38 | 42 | 52 | 64 | 73 | 80 | 83 | 82 | 75 | 64 | 53 | 43 | 62 |
| Avg Precip (In.) | 3.46 | 2.84 | 3.88 | 3.69 | 4.5 | 4.23 | 3.64 | 3.49 | 4.18 | 3.54 | 3.65 | 3.26 | 44.36 |