Harrington, WA 99134 Frost Dates
Frost dates for Harrington, WA, ZIP 99134
The last spring frost here typically falls around 05/31, about 276 days from today. The first fall frost typically arrives around 09/12, about 101 frost-free days later.
Zone 6b (-5 to 0°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 Harrington, not a forecast for this year.
What to do before the first frost
Zone 6b around Harrington has about 2 weeks left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
How much risk comes with planting early here
05/31 is the middle of 30 years of NOAA records, not a promise. Plant by 05/10 and you're betting against frost in roughly 9 years out of 10. 06/28 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Harrington compares
At roughly 101 frost-free days, Harrington places 39,685 of 40,283 ZIP codes in this dataset. Within WA, it ranks 681 of 700.
Learn more
zone vs. frost date explains why Zone 6b and Harrington's frost date answer different questions, and the frost range explains how to read the range around Harrington's dates instead of trusting one.