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 85658
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 85658 in zone 9b (the coldest night of a typical year: 25 to 30°F).
The nearest station, Catalina, AZ, is 15 miles from the ZIP's center: its last spring frost comes after April 2 in half of years and after April 18 in one year in ten.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Catalina, AZCatalina State Park | 15 mi | 2,707 ft | April 2 | April 18 | November 11 | – |
| Casas Adobes, AZTohono Chul | 16 mi | 2,527 ft | February 26 | March 18 | December 4 | – |
| Picacho, AZ8 mi SE | 17 mi | 1,981 ft | February 6 | March 5 | December 9 | 9b |
| Tucson (17 mi NW), AZ | 18 mi | 2,561 ft | February 23 | March 22 | December 6 | – |
| Tucson (11 mi W), AZ | 19 mi | 2,733 ft | February 8 | March 8 | December 10 | – |
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 Catalina
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 5 | April 25 | April 18 | April 4 | November 1 | October 18 |
| 32°F | April 18 | April 8 | April 2 | March 16 | November 11 | October 26 |
| 28°F (hard freeze) | April 1 | March 21 | March 12 | February 22 | November 21 | November 3 |
| 24°F | March 12 | March 3 | February 21 | January 24 | December 4 | November 13 |
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.