FrostDateCheck

Millwood, WA 99021 Frost Dates

When can you plant in Millwood, WA?

Zone 6b

Around 04/26 is the usual last spring frost, about 241 days away. The first fall frost typically arrives around 10/15, about 170 frost-free days later.

Zone 6b (-5 to 0°F average annual minimum) comes from the USDA Plant Hardiness Zone Map; the frost dates above are the 1991-2020 normal at the nearest reporting NOAA station for Millwood, not a forecast for this year.

What to do before the first frost

About 7 weeks of growing season left in Millwood before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.

Why 04/26 isn't a guarantee

04/26 is the middle of 30 years of NOAA records, not a promise. Plant by 04/10 and you're betting against frost in roughly 9 years out of 10. 05/10 is the safer bet, historically only a 1-in-10 chance of frost that late.

How Millwood compares

About 170 days separate Millwood's last and first frost, putting it 29,060 of 40,283 ZIP codes nationally. Within WA, it ranks 500 of 700.

Learn more

local microclimates covers what one yard in Millwood can differ from the 99021 normal. zone vs. frost date covers why Zone 6b and Millwood's frost date answer different questions.