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 80218
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 80218 in zone 6a (the coldest night of a typical year: -10 to -5°F).
The nearest station, Denver Water Dept, CO, is 2 miles from the ZIP's center: its last spring frost comes after April 30 in half of years and after May 13 in one year in ten. By the USDA's method its plant hardiness zone is 6b.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Denver Water Dept, CO | 2 mi | 5,228 ft | April 30 | May 13 | October 12 | 6b |
| Denver-Stapleton, CO | 6 mi | 5,286 ft | May 4 | May 16 | October 8 | 6a |
| Lakewood, CO | 8 mi | 5,640 ft | May 3 | May 18 | October 7 | 6a |
| Wheat Ridge, COWheat Ridge 2 | 8 mi | 5,398 ft | May 5 | May 18 | October 5 | 6a |
| Marston Filter Plant, CO | 9 mi | 5,610 ft | May 2 | May 17 | October 11 | 6a |
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 Denver Water Dept
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 25 | May 14 | May 8 | April 27 | October 4 | September 21 |
| 32°F | May 13 | May 4 | April 30 | April 15 | October 12 | September 28 |
| 28°F (hard freeze) | May 5 | April 26 | April 18 | April 1 | October 21 | October 5 |
| 24°F | April 24 | April 13 | April 4 | March 13 | October 31 | October 14 |
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.