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 98312
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 98312 in zone 8b (the coldest night of a typical year: 15 to 20°F).
The nearest station, Bremerton, WA, is 4 miles from the ZIP's center: its last spring frost comes after March 29 in half of years and after April 24 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 |
|---|---|---|---|---|---|---|
| Bremerton, WA | 4 mi | 110 ft | March 29 | April 24 | November 14 | 8b |
| Quilcene, WA2 mi SW | 18 mi | 123 ft | April 11 | May 1 | October 28 | – |
| Seattle Boeing Field, WA | 22 mi | 20 ft | March 13 | April 1 | November 17 | 9a |
| Tacoma, WATacoma Narrows Airport | 22 mi | 292 ft | March 11 | April 2 | November 21 | 9a |
| Seattle, WASeattle Tacoma International Airport | 23 mi | 370 ft | March 2 | March 23 | November 23 | 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 Bremerton
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 13 | May 2 | April 25 | April 7 | October 27 | October 4 |
| 32°F | April 24 | April 7 | March 29 | March 5 | November 14 | October 26 |
| 28°F (hard freeze) | March 27 | March 9 | February 27 | January 24 | November 30 | November 10 |
| 24°F | February 24 | February 13 | January 26 | December 9 | December 15 | November 23 |
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.