| 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: | May 1 - May 10 | |
| 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 21737 - Glenelg, MD | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 23 | 25 | 32 | 41 | 50 | 59 | 64 | 63 | 56 | 43 | 35 | 27 | 43 |
| Avg Max Temp (°F) | 41 | 45 | 54 | 65 | 75 | 82 | 87 | 85 | 78 | 67 | 56 | 45 | 65 |
| Avg Precip (In.) | 3.42 | 3.04 | 4.2 | 3.37 | 4.64 | 3.89 | 3.96 | 3.52 | 4.08 | 3.55 | 3.58 | 3.45 | 44.71 |