Winthrop, WA 98862 Frost Dates
When can you plant in Winthrop, WA?
The last spring frost here typically falls around 05/15, about 260 days from today. The first fall frost typically arrives around 09/22, about 127 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 Winthrop, not a forecast for this year.
What to do before the first frost
About 4 weeks of growing season left in Winthrop 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
05/15 is the middle of 30 years of NOAA records, not a promise. Plant by 04/30 and you're betting against frost in roughly 9 years out of 10. 06/01 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Winthrop compares
Winthrop's growing season runs about 127 days, ranking 38,649 of 40,283 US ZIP codes measured here, longest to shortest. Within WA, it ranks 644 of 700.
Learn more
the frost range covers how to read the range around Winthrop's dates instead of trusting one. local microclimates covers what one yard in Winthrop can differ from the 98862 normal.