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 98664
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 98664 in zone 8b (the coldest night of a typical year: 15 to 20°F).
The nearest station, Portland, OR, is 2 miles from the ZIP's center: its last spring frost comes after March 13 in half of years and after April 1 in one year in ten. By the USDA's method its plant hardiness zone is 9a.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Portland, ORPortland International Airport | 2 mi | 19 ft | March 13 | April 1 | November 19 | 9a |
| Vancouver, WAVancouver Pearson Airport | 4 mi | 30 ft | March 29 | April 18 | November 9 | 8b |
| Portland Weather Office, OR | 4 mi | 21 ft | March 13 | April 5 | November 22 | – |
| Hazel Dell, WAVancouver (4 mi NNE) | 5 mi | 210 ft | April 26 | May 10 | October 18 | 8b |
| 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 Portland
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) | April 25 | April 14 | April 6 | March 22 | November 2 | October 18 |
| 32°F | April 1 | March 21 | March 13 | February 22 | November 19 | October 29 |
| 28°F (hard freeze) | March 6 | February 25 | February 16 | January 4 | December 5 | November 12 |
| 24°F | February 19 | February 1 | January 13 | December 7 | December 21 | November 24 |
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.