Burien, WA 98126 Frost Dates
Burien, WA: when does the frost end?
Around 03/13 is the usual last spring frost, about 197 days away. Fall's first freeze usually shows up around 11/17, roughly 247 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Burien in Zone 9a (20 to 25°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
With roughly 12 weeks until Burien's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 03/13 isn't a guarantee
03/13 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/20 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/01 and only about 1 year in 10 sees frost after that.
Burien against the rest of the dataset
At roughly 247 frost-free days, Burien places 7,777 of 40,283 ZIP codes in this dataset. Within WA, it ranks 145 of 700.
Learn more
Before leaning on 98126's figures: zone vs. frost date explains why Zone 9a and Burien's frost date answer different questions, while the frost range explains how to read the range around Burien's dates instead of trusting one.