Tacoma, WA 98421 Frost Dates
98421, near Tacoma, WA: the frost window
Typically, the last spring freeze lands around 03/08, roughly 192 days out. Fall's first freeze usually shows up around 11/14, roughly 250 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Tacoma 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
Tacoma's growing season runs out in roughly 11 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
The actual range around Tacoma's last frost
03/08 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 03/31 and only about 1 year in 10 sees frost after that.
Tacoma against the rest of the dataset
At roughly 250 frost-free days, Tacoma places 7,416 of 40,283 ZIP codes in this dataset. Within WA, it ranks 83 of 700.
Learn more
Two guides worth reading on 98421: zone vs. frost date, on why Zone 9a and Tacoma's frost date answer different questions, and the frost range, on how to read the range around Tacoma's dates instead of trusting one.