Mill Creek, WA 98208 Frost Dates
Frost dates for Mill Creek, WA, ZIP 98208
The last spring frost here typically falls around 03/09, about 193 days from today. The first fall frost typically arrives around 11/17, about 250 frost-free days later.
Mill Creek sits in USDA Zone 8b (15 to 20°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
What to do before the first frost
Zone 8b around Mill Creek has about 12 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
The actual range around Mill Creek's last frost
03/09 is the middle of 30 years of NOAA records, not a promise. Plant by 02/15 and you're betting against frost in roughly 9 years out of 10. 03/29 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Mill Creek compares
At roughly 250 frost-free days, Mill Creek places 7,481 of 40,283 ZIP codes in this dataset. Within WA, it ranks 101 of 700.
Learn more
local microclimates explains what one yard in Mill Creek can differ from the 98208 normal, and zone vs. frost date explains why Zone 8b and Mill Creek's frost date answer different questions.