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 85383
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 85383 in zone 9b (the coldest night of a typical year: 25 to 30°F).
The nearest station, Wittmann, AZ, is 13 miles from the ZIP's center: its last spring frost comes after February 5 in half of years and after March 3 in one year in ten. By the USDA's method its plant hardiness zone is 9a.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Wittmann, AZ1 mi SE | 13 mi | 1,683 ft | February 5 | March 3 | December 11 | 9a |
| Castle Hot Springs, AZ | 13 mi | 1,990 ft | January 15 | February 21 | December 22 | 9b |
| Youngtown, AZ | 14 mi | 1,135 ft | January 20 | February 18 | December 15 | 9b |
| Phoenix Deer Valley Municipal Airport, AZ | 15 mi | 1,455 ft | January 8 | February 12 | December 25 | 10a |
| Litchfield Park, AZ | 21 mi | 1,040 ft | January 7 | February 5 | December 24 | 9b |
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 Wittmann
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 2 | March 14 | March 4 | February 6 | November 26 | November 8 |
| 32°F | March 3 | February 16 | February 5 | January 6 | December 11 | November 20 |
| 28°F (hard freeze) | February 12 | January 30 | January 15 | December 14 | December 27 | December 4 |
| 24°F | February 5 | January 22 | January 11 | December 22 | January 7 | December 19 |
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.