| 2023 Hardiness Zone: | Zone 7a: 0°F to 5°F | |
| 2012 Hardiness Zone: | Zone 7a: 0°F to 5°F | |
| 1990 Hardiness Zone: | Zone 7a: 0F 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: | 64c - Piedmont Uplands | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 15 - 30 days Over 86°F |
Annual Climate Data for ZIP Code 21071 - Glyndon, MD | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 22 | 24 | 32 | 41 | 50 | 59 | 64 | 63 | 56 | 44 | 35 | 27 | 43 |
| Avg Max Temp (°F) | 40 | 44 | 53 | 64 | 74 | 82 | 86 | 84 | 77 | 66 | 55 | 44 | 64 |
| Avg Precip (In.) | 3.59 | 2.93 | 4.18 | 3.51 | 4.7 | 3.97 | 3.93 | 3.62 | 4.22 | 3.51 | 3.61 | 3.49 | 45.26 |