Lynnwood, WA 98037 Frost Dates
98037, near Lynnwood, WA: the frost window
Typically, the last spring freeze lands around 03/09, roughly 193 days out. Fall's first freeze usually shows up around 11/17, roughly 250 days after the last spring frost.
Zone 9a (20 to 25°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 Lynnwood, not a forecast for this year.
Stretching the season past the first frost
Lynnwood's growing season runs out in roughly 12 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
How much risk comes with planting early here
03/09 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/15 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 03/29 and only about 1 year in 10 sees frost after that.
Lynnwood against the rest of the dataset
At roughly 250 frost-free days, Lynnwood places 7,453 of 40,283 ZIP codes in this dataset. Within WA, it ranks 94 of 700.
Learn more
Two guides worth reading on 98037: local microclimates, on what one yard in Lynnwood can differ from the 98037 normal, and zone vs. frost date, on why Zone 9a and Lynnwood's frost date answer different questions.