Newcastle, WA 98056 Frost Dates
When can you plant in Newcastle, WA?
Typically, the last spring freeze lands around 03/13, roughly 197 days out. The first fall frost typically arrives around 11/17, about 247 frost-free days later.
The USDA Plant Hardiness Zone Map puts Newcastle in Zone 9a (20 to 25°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 12 weeks of growing season left in Newcastle before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 03/13 isn't a guarantee
03/13 is the middle of 30 years of NOAA records, not a promise. Plant by 02/20 and you're betting against frost in roughly 9 years out of 10. 04/01 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Newcastle compares
At roughly 247 frost-free days, Newcastle places 7,813 of 40,283 ZIP codes in this dataset. Within WA, it ranks 156 of 700.
Learn more
local microclimates covers what one yard in Newcastle can differ from the 98056 normal. zone vs. frost date covers why Zone 9a and Newcastle's frost date answer different questions.