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 83203
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 83203 in zone 5b (the coldest night of a typical year: -15 to -10°F).
The nearest station, Fort Hall, ID, is 1 miles from the ZIP's center: its last spring frost comes after May 20 in half of years and after June 12 in one year in ten. By the USDA's method its plant hardiness zone is 5b.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Fort Hall, ID1 mi NNE | 1 mi | 4,465 ft | May 20 | June 12 | September 20 | 5b |
| Pocatello (2 mi NE), ID | 9 mi | 4,832 ft | May 16 | June 6 | October 2 | 6b |
| Pocatello, IDPocatello Regional Airport | 10 mi | 4,478 ft | May 23 | June 13 | September 18 | 6a |
| Pocatello City, ID | 10 mi | 4,460 ft | May 2 | May 18 | October 11 | – |
| Blackfoot, IDBlackfoot Fire Dept | 12 mi | 4,499 ft | May 5 | May 22 | October 3 | – |
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 Fort Hall
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) | June 27 | June 17 | June 10 | May 23 | September 7 | August 20 |
| 32°F | June 12 | May 31 | May 20 | May 6 | September 20 | September 1 |
| 28°F (hard freeze) | May 23 | May 11 | May 6 | April 23 | October 4 | September 15 |
| 24°F | May 7 | April 30 | April 24 | April 8 | October 17 | September 29 |
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.