Sammamish, WA 98075 Frost Dates
Sammamish, WA: when does the frost end?
Typically, the last spring freeze lands around 03/30, roughly 214 days out. Fall's first freeze usually shows up around 11/07, roughly 223 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Sammamish in Zone 8b (15 to 20°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 10 weeks until Sammamish's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 03/30 isn't a guarantee
03/30 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/04 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/21 and only about 1 year in 10 sees frost after that.
Sammamish against the rest of the dataset
Sammamish's growing season runs about 223 days, ranking 12,001 of 40,283 US ZIP codes measured here, longest to shortest. Within WA, it ranks 228 of 700.
Learn more
Before leaning on 98075's figures: zone vs. frost date explains why Zone 8b and Sammamish's frost date answer different questions, while the frost range explains how to read the range around Sammamish's dates instead of trusting one.