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 97078
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 97078 in zone 8b (the coldest night of a typical year: 15 to 20°F).
The nearest station, Nature Park-Beaverton, OR, is 3 miles from the ZIP's center: its last spring frost comes after February 11 in half of years and after March 5 in one year in ten.
| Station | Distance | Elevation | Last frost (median) | 1 in 10 after | First frost (median) | Hardiness zone |
|---|---|---|---|---|---|---|
| Nature Park-Beaverton, OR | 3 mi | 185 ft | February 11 | March 5 | December 5 | – |
| Beaverton, OR2 mi SSW | 4 mi | 270 ft | April 1 | April 26 | November 6 | – |
| Hillsboro, ORPortland-Hillsboro Airport | 5 mi | 204 ft | April 16 | May 3 | October 23 | 8b |
| Portland Kgw-Tv, OR | 10 mi | 159 ft | February 25 | March 21 | December 1 | 9a |
| Forest Grove, OR | 11 mi | 180 ft | April 16 | May 5 | October 26 | 8a |
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 Nature Park-Beaverton
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 15 | March 31 | March 23 | February 25 | November 13 | October 26 |
| 32°F | March 5 | February 22 | February 11 | December 26 | December 5 | November 11 |
| 28°F (hard freeze) | February 16 | January 28 | January 6 | December 2 | December 21 | November 24 |
| 24°F | February 11 | January 23 | January 1 | December 4 | December 30 | December 2 |
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.