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 92223
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 92223 in zone 9b (the coldest night of a typical year: 25 to 30°F).
The nearest station, San Jacinto, CA, is 10 miles from the ZIP's center: its last spring frost comes after January 31 in half of years and after February 28 in one year in ten. By the USDA's method its plant hardiness zone is 9b.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| San Jacinto, CA | 10 mi | 1,525 ft | January 31 | February 28 | December 10 | 9b |
| Redlands, CA | 14 mi | 1,410 ft | January 27 | February 28 | December 19 | 10a |
| Hemet, CA | 15 mi | 1,811 ft | January 10 | February 25 | December 23 | 9b |
| Idyllwild Fire Dept, CA | 20 mi | 5,380 ft | May 16 | June 5 | October 24 | 8a |
| Big Bear Lake, CA | 21 mi | 6,753 ft | May 27 | June 9 | October 4 | 7b |
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 San Jacinto
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) | April 8 | March 20 | March 5 | February 6 | November 24 | November 5 |
| 32°F | February 28 | February 14 | January 31 | December 31 | December 10 | November 22 |
| 28°F (hard freeze) | January 29 | January 12 | January 3 | December 11 | December 21 | December 2 |
| 24°F | January 14 | January 5 | January 1 | December 10 | December 31 | December 9 |
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.