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 15620
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 15620 in zone 6b (the coldest night of a typical year: -5 to 0°F).
The nearest station, Loyalhanna, PA, is 11 miles from the ZIP's center: its last spring frost comes after May 2 in half of years and after May 18 in one year in ten.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Loyalhanna, PALoyalhanna Lake | 11 mi | 990 ft | May 2 | May 18 | October 14 | – |
| Mount Pleasant, PA | 11 mi | 1,003 ft | May 1 | May 19 | October 13 | – |
| Rector (3 mi SSW), PA | 11 mi | 1,330 ft | May 5 | May 22 | October 6 | – |
| Laurel Mountain, PA | 12 mi | 2,760 ft | April 26 | May 13 | October 17 | – |
| Donegal, PA2 mi NW | 14 mi | 1,800 ft | April 30 | May 18 | October 17 | – |
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 Loyalhanna
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 31 | May 21 | May 14 | April 29 | October 3 | September 22 |
| 32°F | May 18 | May 9 | May 2 | April 18 | October 14 | October 2 |
| 28°F (hard freeze) | May 8 | April 28 | April 22 | April 7 | October 25 | October 9 |
| 24°F | April 22 | April 15 | April 8 | March 26 | November 4 | October 22 |
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.