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 93550
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 93550 in zone 9a (the coldest night of a typical year: 20 to 25°F).
The nearest station, Pearblossom, CA, is 11 miles from the ZIP's center: its last spring frost comes after March 13 in half of years and after April 17 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 |
|---|---|---|---|---|---|---|
| Pearblossom, CA | 11 mi | 3,101 ft | March 13 | April 17 | December 1 | 9a |
| Mount Wilson CBS, CA | 12 mi | 5,710 ft | April 28 | May 27 | November 15 | 8b |
| Palmdale station, CA | 12 mi | 2,612 ft | March 10 | April 11 | November 19 | – |
| Palmdale, CAPalmdale Airport | 15 mi | 2,524 ft | March 18 | April 11 | November 15 | 8b |
| Pasadena, CA | 19 mi | 864 ft | January 8 | February 17 | January 7 | 10b |
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 Pearblossom
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 9 | April 25 | April 14 | March 14 | November 16 | October 28 |
| 32°F | April 17 | April 1 | March 13 | February 10 | December 1 | November 12 |
| 28°F (hard freeze) | March 18 | February 24 | February 9 | December 30 | December 12 | November 25 |
| 24°F | February 18 | January 31 | January 10 | December 11 | December 30 | December 5 |
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.