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 19901
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 19901 in zone 7b (the coldest night of a typical year: 5 to 10°F).
The nearest station, Dover, DE, is 3 miles from the ZIP's center: its last spring frost comes after April 4 in half of years and after April 17 in one year in ten. By the USDA's method its plant hardiness zone is 7b.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Dover, DE | 3 mi | 30 ft | April 4 | April 17 | November 4 | 7b |
| Seabrook Farms, NJ | 25 mi | 104 ft | April 10 | April 25 | November 1 | 7b |
| Millville, NJMillville Municipal Airport | 25 mi | 70 ft | April 24 | May 10 | October 23 | 7a |
| Greenwood, DE2 mi NE | 26 mi | 45 ft | April 11 | April 28 | October 30 | 7b |
| Woodstown, NJWoodstown Pittsgrov (4 mi E) | 30 mi | 98 ft | April 11 | April 27 | November 3 | – |
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 Dover
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) | May 5 | April 23 | April 17 | April 3 | October 25 | October 12 |
| 32°F | April 17 | April 9 | April 4 | March 22 | November 4 | October 23 |
| 28°F (hard freeze) | April 5 | March 30 | March 25 | March 8 | November 16 | November 3 |
| 24°F | March 27 | March 19 | March 13 | February 26 | November 30 | November 11 |
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.