| 2023 Hardiness Zone: | Zone 9a: 20°F to 25°F Zone 9b: 25°F to 30°F | |
| 2012 Hardiness Zone: | Zone 8b: 15°F to 20°F Zone 9a: 20°F to 25°F | |
| 1990 Hardiness Zone: | Zone 8b: 15F to 20F | |
| Average First Frost Date: | Dec. 1 - Dec. 10 | |
| Average Last Frost Date: | Mar. 1 - Mar. 10 | |
| Koppen-Geiger Climate Zone: | Cfa - Humid Subtropical Climate | |
| Ecoregion: | 75j - Sea Islands/Coastal Marsh | |
| Current Drought Status: | Exceptional Drought | |
| Heat Zone Days: | 61 - 90 days Over 86°F |
Annual Climate Data for ZIP Code 29920 - Saint Helena Island, SC | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | Annual |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg Min Temp (°F) | 38 | 39 | 46 | 54 | 63 | 70 | 74 | 72 | 68 | 57 | 48 | 40 | 56 |
| Avg Max Temp (°F) | 58 | 61 | 67 | 74 | 81 | 86 | 89 | 88 | 84 | 76 | 68 | 60 | 74 |
| Avg Precip (In.) | 4.02 | 3.2 | 3.82 | 2.97 | 3.12 | 4.94 | 5.56 | 7.4 | 5.57 | 3.27 | 2.72 | 3.32 | 49.91 |