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 85203
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 85203 in zone 9b (the coldest night of a typical year: 25 to 30°F).
The nearest station, Tempe, AZ, is 7 miles from the ZIP's center: its last spring frost comes after February 13 in half of years and after March 9 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 |
|---|---|---|---|---|---|---|
| Tempe, AZTempe ASU | 7 mi | 1,167 ft | February 13 | March 9 | December 5 | 9b |
| Mesa, AZEast Mesa | 9 mi | 1,518 ft | February 1 | February 28 | December 10 | 9b |
| Phoenix, AZPhoenix Sky Harbor International Airport | 12 mi | 1,107 ft | January 5 | January 22 | January 3 | 10a |
| Fountain Hills, AZ | 12 mi | 1,580 ft | January 6 | February 11 | December 28 | – |
| Scottsdale, AZScottsdale Municipal Airport | 13 mi | 1,473 ft | January 6 | February 7 | December 26 | 10a |
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 Tempe
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 7 | March 20 | March 8 | February 14 | November 26 | November 7 |
| 32°F | March 9 | February 24 | February 13 | January 12 | December 5 | November 18 |
| 28°F (hard freeze) | February 19 | February 1 | January 16 | December 19 | December 19 | November 27 |
| 24°F | January 28 | January 11 | January 3 | December 6 | December 31 | December 4 |
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.