Frost dates by ZIP code: The nearest NOAA stations to your ZIP, 1991-2020 normals
Enter a five-digit ZIP code. PlainClimate finds its center (Census Bureau 2024) and the five nearest NOAA stations with frost dates, and shows each station's last spring and first autumn 32°F dates with its distance and elevation.
Frost dates near ZIP 29418
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 29418 in zone 9a (the coldest night of a typical year: 20 to 25°F).
The nearest station, Charleston, SC, is 3 miles from the ZIP's center: its last spring frost comes after March 7 in half of years and after March 27 in one year in ten. By the USDA's method its plant hardiness zone is 9a.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Charleston, SCCharleston International Airport | 3 mi | 40 ft | March 7 | March 27 | November 27 | 9a |
| Summerville, SC4 mi W | 12 mi | 65 ft | March 22 | April 7 | November 12 | – |
| Charleston City, SC | 13 mi | 10 ft | February 4 | March 4 | December 30 | 9b |
| Sullivan's Island, SCSullivans Island | 17 mi | 5 ft | March 13 | March 30 | November 30 | – |
| Moncks Corner, SC4 mi N | 24 mi | 49 ft | March 10 | March 29 | November 26 | – |
Frost comes later in spring at higher and colder stations and earlier in low, open ground: prefer a station at a similar elevation to yours. Hardiness zone in the table: the USDA's rule (the average of each year's coldest night, 1991-2020) applied to the station's own record.
Every frost threshold at Charleston
NOAA publishes the dates for several temperatures and odds. A 30% spring date means a 3-in-10 chance of a later frost (the convention almanacs use); 50% is the median; 10% the cautious date.
| Threshold | Spring, 10% | Spring, 30% | Spring, 50% | Spring, 90% | Autumn, 50% | Autumn, 10% |
|---|---|---|---|---|---|---|
| 36°F (light frost) | April 6 | March 29 | March 21 | February 28 | November 13 | November 1 |
| 32°F | March 27 | March 15 | March 7 | February 12 | November 27 | November 8 |
| 28°F (hard freeze) | March 14 | March 1 | February 20 | January 21 | December 15 | November 21 |
| 24°F | March 3 | February 12 | January 31 | January 2 | January 1 | December 4 |
Source: NOAA NCEI 1991-2020 annual normals; ZIP centers: Census Bureau 2024 Gazetteer; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. Autumn 10%: one year in ten has its first frost before this date.