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 18015
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 18015 in zone 7a (the coldest night of a typical year: 0 to 5°F).
The nearest station, Springtown (1 mi NNE), PA, is 5 miles from the ZIP's center: its last spring frost comes after April 21 in half of years and after May 6 in one year in ten. By the USDA's method its plant hardiness zone is 7a.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Springtown (1 mi NNE), PA | 5 mi | 860 ft | April 21 | May 6 | October 22 | 7a |
| Allentown, PAAllentown Lehigh Valley International Airport | 6 mi | 390 ft | April 20 | May 6 | October 24 | 7a |
| Bucksville, PA | 10 mi | 387 ft | April 29 | May 15 | October 16 | 6b |
| Phillipsburg, NJPhillipsburg-Easton Bridge | 12 mi | 232 ft | April 18 | May 5 | October 25 | 7a |
| Sellersville, PA | 16 mi | 302 ft | April 26 | May 12 | October 17 | 7a |
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 Springtown (1 mi NNE)
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 18 | May 8 | May 2 | April 19 | October 10 | September 30 |
| 32°F | May 6 | April 27 | April 21 | April 8 | October 22 | October 7 |
| 28°F (hard freeze) | April 23 | April 14 | April 8 | March 29 | November 3 | October 18 |
| 24°F | April 11 | April 4 | March 31 | March 16 | November 15 | November 1 |
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.