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 98373
The USDA's 2023 Plant Hardiness Zone Map puts ZIP 98373 in zone 8b (the coldest night of a typical year: 15 to 20°F).
The nearest station, McMillin, WA, is 3 miles from the ZIP's center: its last spring frost comes after April 11 in half of years and after April 29 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 |
|---|---|---|---|---|---|---|
| McMillin, WAMcMillin Reservoir | 3 mi | 579 ft | April 11 | April 29 | October 30 | 8b |
| Tacoma #1, WA | 8 mi | 25 ft | March 8 | March 31 | November 14 | 9a |
| Tacoma, WATacoma Narrows Airport | 14 mi | 292 ft | March 11 | April 2 | November 21 | 9a |
| Buckley, WA1 mi NE | 15 mi | 685 ft | April 7 | April 27 | October 30 | 8b |
| Mud Mountain Dam, WA | 18 mi | 1,308 ft | April 18 | May 10 | October 31 | 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 McMillin
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 17 | May 7 | May 1 | April 17 | October 12 | September 30 |
| 32°F | April 29 | April 19 | April 11 | March 23 | October 30 | October 13 |
| 28°F (hard freeze) | April 8 | March 27 | March 16 | February 19 | November 14 | October 28 |
| 24°F | March 16 | February 28 | February 19 | December 31 | December 1 | November 8 |
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.