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 97224

The USDA's 2023 Plant Hardiness Zone Map puts ZIP 97224 in zone 9a (the coldest night of a typical year: 20 to 25°F).

The nearest station, Beaverton, OR, is 4 miles from the ZIP's center: its last spring frost comes after April 1 in half of years and after April 26 in one year in ten.

The nearest NOAA stations with frost dates (32°F)
StationDistanceElevationLast frost (median)1 in 10 afterFirst frost (median)Hardiness zone
Beaverton, OR2 mi SSW4 mi270 ftApril 1April 26November 6–
Nature Park-Beaverton, OR7 mi185 ftFebruary 11March 5December 5–
North Willamette Experiment Station, OR9 mi150 ftMarch 18April 10November 13–
Rex (1 mi S), OR9 mi515 ftMarch 21April 19November 22–
Portland Kgw-Tv, OR9 mi159 ftFebruary 25March 21December 19a

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 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.

Beaverton, OR: last spring and first autumn dates by threshold and chance (NOAA 1991-2020)
ThresholdSpring, 10%Spring, 30%Spring, 50%Spring, 90%Autumn, 50%Autumn, 10%
36°F (light frost)May 16May 4April 28April 11October 21October 4
32°FApril 26April 11April 1March 5November 6October 19
28°F (hard freeze)March 26March 8February 26January 23November 30November 6
24°FFebruary 28February 16February 1December 15December 19November 18

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.

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