Morton, WA 98336 Frost Dates
When can you plant in Morton, WA?
Around 05/22 is the usual last spring frost, about 267 days away. The first fall frost typically arrives around 10/03, about 134 frost-free days later.
The USDA Plant Hardiness Zone Map puts Morton in Zone 8a (10 to 15°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
About 5 weeks of growing season left in Morton before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
How much risk comes with planting early here
05/22 is the middle of 30 years of NOAA records, not a promise. Plant by 05/03 and you're betting against frost in roughly 9 years out of 10. 06/09 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Morton compares
At roughly 134 frost-free days, Morton places 37,986 of 40,283 ZIP codes in this dataset. Within WA, it ranks 629 of 700.
Learn more
local microclimates covers what one yard in Morton can differ from the 98336 normal. zone vs. frost date covers why Zone 8a and Morton's frost date answer different questions.