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 31405
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 31405 in zone 9a (the coldest night of a typical year: 20 to 25°F).
The nearest station, Savannah, GA, is 7 miles from the ZIP's center: its last spring frost comes after March 2 in half of years and after March 25 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 |
|---|---|---|---|---|---|---|
| Savannah, GASavannah/Hilton Head International Airport | 7 mi | 46 ft | March 2 | March 25 | November 30 | 9a |
| Fort Stewart, GA | 29 mi | 92 ft | March 5 | March 26 | November 29 | 9a |
| Brooklet, GA1 mi W | 37 mi | 180 ft | March 7 | March 27 | November 21 | 9a |
| Beaufort Wastewater Treatment Plant, SC | 37 mi | 25 ft | March 3 | March 20 | December 9 | – |
| Beaufort, SCBeaufort Marine Corps Air Station | 41 mi | 37 ft | February 28 | March 21 | December 3 | 9a |
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 Savannah
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 27 | March 19 | February 26 | November 16 | November 1 |
| 32°F | March 25 | March 12 | March 2 | February 4 | November 30 | November 11 |
| 28°F (hard freeze) | March 13 | February 26 | February 13 | January 15 | December 22 | November 24 |
| 24°F | February 28 | February 6 | January 28 | December 29 | January 4 | December 7 |
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.