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 84111
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 84111 in zone 7b (the coldest night of a typical year: 5 to 10°F).
The nearest station, Salt Lake Triad Center, UT, is 1 miles from the ZIP's center: its last spring frost comes after March 31 in half of years and after April 19 in one year in ten.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Salt Lake Triad Center, UT | 1 mi | 4,280 ft | March 31 | April 19 | November 8 | – |
| Salt Lake City E Bench, UT | 4 mi | 4,850 ft | April 25 | May 10 | October 18 | – |
| Salt Lake City, UTSalt Lake City International Airport | 5 mi | 4,225 ft | April 8 | April 30 | October 31 | 7a |
| City Creek Water Treatment Plant, UT | 5 mi | 5,340 ft | May 13 | May 31 | October 7 | 6b |
| North Salt Lake, UTBountiful-Val Verda | 7 mi | 4,540 ft | April 24 | May 14 | October 19 | 7b |
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 Triad Center
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 9 | April 26 | April 18 | March 28 | October 28 | October 12 |
| 32°F | April 19 | April 7 | March 31 | March 7 | November 8 | October 23 |
| 28°F (hard freeze) | April 2 | March 15 | March 8 | February 17 | November 18 | November 1 |
| 24°F | March 10 | February 28 | February 19 | January 31 | November 29 | November 11 |
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.