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 93237
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 93237 in zone 9b (the coldest night of a typical year: 25 to 30°F).
The nearest station, Three Rivers, CA, is 2 miles from the ZIP's center: its last spring frost comes after March 16 in half of years and after April 14 in one year in ten.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Three Rivers, CAThree Rivers Edison Powerhouse 1 | 2 mi | 1,140 ft | March 16 | April 14 | November 26 | – |
| Ash Mountain, CA | 5 mi | 1,708 ft | March 12 | April 16 | December 9 | 9b |
| Lemon Cove, CA | 9 mi | 513 ft | February 5 | March 20 | December 8 | 9b |
| Lodgepole, CA | 13 mi | 6,735 ft | June 8 | June 29 | September 20 | 6b |
| Grant Grove, CA | 18 mi | 6,580 ft | June 1 | June 15 | October 7 | – |
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 Three Rivers
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 4 | April 21 | April 13 | March 21 | November 10 | October 21 |
| 32°F | April 14 | April 1 | March 16 | February 5 | November 26 | November 5 |
| 28°F (hard freeze) | March 18 | February 15 | January 30 | December 24 | December 11 | November 22 |
| 24°F | February 7 | January 19 | January 3 | December 9 | December 26 | December 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.