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 98661
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 98661 in zone 8b (the coldest night of a typical year: 15 to 20°F).
The nearest station, Vancouver, WA, is 2 miles from the ZIP's center: its last spring frost comes after March 29 in half of years and after April 18 in one year in ten. By the USDA's method its plant hardiness zone is 8b.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Vancouver, WAVancouver Pearson Airport | 2 mi | 30 ft | March 29 | April 18 | November 9 | 8b |
| Hazel Dell, WAVancouver (4 mi NNE) | 3 mi | 210 ft | April 26 | May 10 | October 18 | 8b |
| Portland, ORPortland International Airport | 4 mi | 19 ft | March 13 | April 1 | November 19 | 9a |
| Portland Weather Office, OR | 7 mi | 21 ft | March 13 | April 5 | November 22 | – |
| Portland Kgw-Tv, OR | 9 mi | 159 ft | February 25 | March 21 | December 1 | 9a |
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 Vancouver
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 10 | April 30 | April 24 | April 3 | October 24 | October 7 |
| 32°F | April 18 | April 5 | March 29 | March 6 | November 9 | October 22 |
| 28°F (hard freeze) | March 27 | March 12 | March 3 | February 4 | November 26 | November 3 |
| 24°F | March 1 | February 19 | February 7 | December 26 | December 14 | November 16 |
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.