Northport, WA 99157 Frost Dates
99157, near Northport, WA: the frost window
Typically, the last spring freeze lands around 05/08, roughly 253 days out. Fall's first freeze usually shows up around 10/01, roughly 143 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Northport in Zone 6b (-5 to 0°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
Northport's growing season runs out in roughly 5 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 05/08 isn't a guarantee
05/08 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/27 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/26 and only about 1 year in 10 sees frost after that.
Northport against the rest of the dataset
At roughly 143 frost-free days, Northport places 36,619 of 40,283 ZIP codes in this dataset. Within WA, it ranks 609 of 700.
Learn more
Two guides worth reading on 99157: the frost range, on how to read the range around Northport's dates instead of trusting one, and local microclimates, on what one yard in Northport can differ from the 99157 normal.