Frost dates for Sullivans Island, SC
At Sullivans Island, the median last spring frost (32°F) is Mar 13 and the median first fall frost is Nov 30, for a typical growing season of 262 days. For a 90% chance that the last frost has passed, wait until Mar 30. Nearby ZIP codes are in USDA hardiness zone 9a.
- Mar 13Last spring frost (median)50% chance of 32°F after this date
- Mar 30Safer planting date10% chance of 32°F after this date
- Nov 30First fall frost (median)50% chance of 32°F by this date
- 262 daysGrowing season (median)between 32°F freezes
Last spring frost dates
The chance that the temperature drops to the threshold after each date.
| Temperature | 90% chance later | 50% chance later | 10% chance later |
|---|---|---|---|
| 36°F | Mar 6 | Mar 25 | Apr 10 |
| 32°F | Feb 19 | Mar 13 | Mar 30 |
| 28°F | Feb 1 | Mar 1 | Mar 22 |
| 24°F | Jan 9 | Feb 9 | Mar 13 |
First fall frost dates
The chance that the temperature has dropped to the threshold by each date.
| Temperature | 10% chance by | 50% chance by | 90% chance by |
|---|---|---|---|
| 36°F | Nov 1 | Nov 16 | Dec 5 |
| 32°F | Nov 11 | Nov 30 | Dec 24 |
| 28°F | Nov 25 | Dec 16 | Jan 10 |
| 24°F | Dec 5 | Jan 2 | Jan 29 |
Growing season length
Days between the last spring and first fall freeze, as the length reached in 9, 5 and 1 out of 10 years.
| Temperature | 9 in 10 years at least | 5 in 10 years at least | 1 in 10 years at least |
|---|---|---|---|
| 36°F | 212 days | 236 days | 263 days |
| 32°F | 232 days | 262 days | 291 days |
| 28°F | 259 days | 288 days | 320 days |
| 24°F | 285 days | 317 days | 356 days |
Chance of a freeze in any year
| Temperature | Chance per year |
|---|---|
| 36°F | 100% |
| 32°F | 100% |
| 28°F | 100% |
| 24°F | 96% |
ZIP codes whose closest station is this one
| ZIP | Hardiness zone | Avg. extreme low | Distance |
|---|---|---|---|
| 29482 | 9a | 20 to 25°F | 3 km |
| 29464 | 9a | 20 to 25°F | 6 km |
| 29451 | 9a | 20 to 25°F | 12 km |
| 29466 | 9a | 20 to 25°F | 14 km |
Not the official USDA Plant Hardiness Zone Map. Zones shown here are the values published in the USDA-ARS / Oregon State University PRISM Group 2023 ZIP code tables, shown unaltered. For the official interactive map, visit planthardiness.ars.usda.gov.
About this station
- NOAA station ID USC00388405, at 32.7617, -79.8572, elevation 2 m (5 ft).
- Data quality: Representative (10+ years), 24 years of freeze data.
- Average days per year at or below 32°F: 18.
- Frost risk changes over short distances. Valleys and low spots freeze earlier than hillsides and city centers.
Nearby weather stations
- Charleston City (7 km)
- Charleston Intl Airport (23 km)
- Summerville 4w (47 km)
- Edisto Island Middleton Plantation (47 km)
- McClellanville (50 km)
- Edisto Beach State Park (50 km)
- Moncks Corner 4 N (55 km)
- Jamestown (60 km)
Sources
- NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020, annual/seasonal normals by station (version 1.0.1), file dated June 27, 2023; documentation.
- USDA Agricultural Research Service and PRISM Group, Oregon State University, 2023 Plant Hardiness Zone Map ZIP code tables (CONUS, Alaska, Hawaii, Puerto Rico), files dated November 17, 2023. Data © PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed November 1, 2026. Official map: planthardiness.ars.usda.gov.
- U.S. Census Bureau, 2024 Gazetteer ZIP Code Tabulation Areas file, dated August 30, 2024 (ZIP centroids used to find the nearest station).
Freeze dates are 30-year probabilities, not forecasts. Check your local forecast before planting tender plants.
All South Carolina stations · How frost dates are calculated