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 84123
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 84123 in zone 7b (the coldest night of a typical year: 5 to 10°F).
The nearest station, Salt Lake City E Bench, UT, is 8 miles from the ZIP's center: its last spring frost comes after April 25 in half of years and after May 10 in one year in ten.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Salt Lake City E Bench, UT | 8 mi | 4,850 ft | April 25 | May 10 | October 18 | – |
| Cottonwood Heights, UTCottonwood Weir | 8 mi | 4,986 ft | April 29 | May 30 | October 22 | 7a |
| Salt Lake Triad Center, UT | 8 mi | 4,280 ft | March 31 | April 19 | November 8 | – |
| Salt Lake City, UTSalt Lake City International Airport | 9 mi | 4,225 ft | April 8 | April 30 | October 31 | 7a |
| City Creek Water Treatment Plant, UT | 12 mi | 5,340 ft | May 13 | May 31 | October 7 | 6b |
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 Salt Lake City E Bench
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 29 | May 15 | May 8 | April 24 | October 8 | September 28 |
| 32°F | May 10 | May 1 | April 25 | April 7 | October 18 | October 5 |
| 28°F (hard freeze) | April 26 | April 15 | April 7 | March 19 | October 29 | October 15 |
| 24°F | April 11 | March 31 | March 22 | March 3 | November 9 | October 22 |
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.