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 85653
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 85653 in zone 9b (the coldest night of a typical year: 25 to 30°F).
The nearest station, Tucson (17 mi NW), AZ, is 15 miles from the ZIP's center: its last spring frost comes after February 23 in half of years and after March 22 in one year in ten.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Tucson (17 mi NW), AZ | 15 mi | 2,561 ft | February 23 | March 22 | December 6 | – |
| Tucson (11 mi W), AZ | 17 mi | 2,733 ft | February 8 | March 8 | December 10 | – |
| Picacho, AZ8 mi SE | 17 mi | 1,981 ft | February 6 | March 5 | December 9 | 9b |
| Casas Adobes, AZTohono Chul | 24 mi | 2,527 ft | February 26 | March 18 | December 4 | – |
| Tucson U Of A #1, AZ | 24 mi | 2,315 ft | February 11 | March 7 | December 2 | 9a |
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 Tucson (17 mi NW)
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 10 | March 26 | March 15 | February 22 | November 24 | November 7 |
| 32°F | March 22 | March 5 | February 23 | January 15 | December 6 | November 18 |
| 28°F (hard freeze) | March 1 | February 7 | January 22 | December 19 | December 19 | November 30 |
| 24°F | February 12 | January 31 | January 9 | December 13 | January 1 | December 10 |
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.