Sullivan's Island, SC frost dates
From NOAA weather station Sullivans Is (USC00388405), elevation 5 ft. The nearest Census place to the station coordinates is Sullivan's Island town, 1.6 miles away.
Summary
In the 1991–2020 record, the median last spring freeze (32°F) at Sullivans Is is Mar 13 and the median first fall freeze is Nov 30, for a typical freeze-free season of 262 days. In about 1 year in 10 the last spring freeze comes after Mar 30, and in about 1 year in 10 the first fall freeze arrives by Nov 11. The station averages 18 nights per year with a low of 32°F or colder.
Compared with the median of 103 South Carolina stations in this dataset, the median last freeze here is 13 days earlier than the state median (Mar 26), the median first freeze is 21 days later than the state median (Nov 9), and the growing season ranks #10 of 103 by length (longest = #1). The spread between the 90% and 10% spring dates is 39 days, a measure of how variable spring is here.
Freeze probability table
| Threshold | Last spring occurrence | First fall occurrence | Season length (days) 90% / 50% / 10% | ||||
|---|---|---|---|---|---|---|---|
| Early (90% chance of a later freeze) | Median (50%) | Cautious (10% chance of a later freeze) | Early (10% chance by then) | Median (50%) | Late (90% chance by then) | ||
| 36°F (light frost possible) | Mar 6 | Mar 25 | Apr 10 | Nov 1 | Nov 16 | Dec 5 | 212 / 236 / 263 |
| 32°F (freeze) | Feb 19 | Mar 13 | Mar 30 | Nov 11 | Nov 30 | Dec 24 | 232 / 262 / 291 |
| 28°F (hard freeze) | Feb 1 | Mar 1 | Mar 22 | Nov 25 | Dec 16 | Jan 10 | 259 / 288 / 320 |
Read the spring “Cautious” column as the safer planting date: only about 1 year in 10 has a freeze after it. NOAA computes these from daily minimum temperatures at the station; your yard can differ, especially in low spots or at a different elevation.
Planting calendar for Sullivan's Island
Pick how much frost risk you accept. The calendar applies generic, extension-published timing rules to this station’s dates. See the rules and sources.
| Crop | Start seeds indoors | Plant outdoors (spring) | Latest fall planting (est.) | Days to harvest |
|---|
Fall estimates count back from the median first fall freeze (32°F for tender crops, 28°F hard freeze for cool-season crops) by the longer days-to-harvest figure. These are rough planning aids, not recommendations for any specific variety; check seed packets and your county extension office.
Towns that use this station as their nearest
Census places within 15 miles whose closest station in this dataset is Sullivans Is: Sullivan's Island (2 mi), Mount Pleasant (3 mi), Isle of Palms (7 mi).
Nearby stations
- Charleston City, SC — 5 mi; median last freeze Feb 4, first freeze Dec 30
- Charleston Intl AP, SC — 14 mi; median last freeze Mar 7, first freeze Nov 27
- Summerville 4W, SC — 29 mi; median last freeze Mar 22, first freeze Nov 12
- Edisto Is Middleton Plantation, SC — 29 mi; median last freeze Mar 1, first freeze Dec 6
- Mcclellanville, SC — 31 mi; median last freeze Mar 17, first freeze Nov 21
About this station’s data
- Station ID: USC00388405 · Latitude 32.7617, longitude -79.8572 · Elevation 2 m (5 ft)
- NOAA completeness flag: R — Representative: meets WMO standards for 10 or more years; gaps filled from surrounding stations. Years of data used: 24.
- Source file: USC00388405.csv (NOAA NCEI 1991–2020 annual/seasonal normals).
Raw values from the NOAA file (32°F)
| Field | Value |
|---|---|
ANN-TMIN-PRBLST-T32FP10 | 03/30 |
ANN-TMIN-PRBLST-T32FP50 | 03/13 |
ANN-TMIN-PRBLST-T32FP90 | 02/19 |
ANN-TMIN-PRBFST-T32FP10 | 11/11 |
ANN-TMIN-PRBFST-T32FP50 | 11/30 |
ANN-TMIN-PRBFST-T32FP90 | 12/24 |
ANN-TMIN-PRBGSL-T32FP10 | 291.0 |
ANN-TMIN-PRBGSL-T32FP50 | 262.0 |
ANN-TMIN-PRBGSL-T32FP90 | 232.0 |