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 91501
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 91501 in zone 10a (the coldest night of a typical year: 30 to 35°F).
The nearest station, Burbank Valley Pump Plant, CA, is 3 miles from the ZIP's center: its last spring frost comes after January 2 in half of years and after January 31 in one year in ten. By the USDA's method its plant hardiness zone is 10a.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Burbank Valley Pump Plant, CA | 3 mi | 655 ft | January 2 | January 31 | December 26 | 10a |
| Burbank, CABurbank Glendale Pasadena Airport | 4 mi | 741 ft | December 31 | January 15 | December 28 | 10a |
| Pasadena, CA | 9 mi | 864 ft | January 8 | February 17 | January 7 | 10b |
| Van Nuys Airport, CA | 11 mi | 770 ft | December 31 | January 27 | December 30 | 10a |
| Mount Wilson CBS, CA | 13 mi | 5,710 ft | April 28 | May 27 | November 15 | 8b |
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 Burbank Valley Pump Plant
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) | March 10 | February 23 | February 5 | December 31 | December 12 | November 23 |
| 32°F | January 31 | January 10 | January 2 | December 11 | December 26 | 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.