Ione, WA 83848 Frost Dates
Frost dates for Ione, WA, ZIP 83848
Around 05/20 is the usual last spring frost, about 265 days away. The first fall frost typically arrives around 09/13, about 114 frost-free days later.
Zone 6a (-10 to -5°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 Ione, not a forecast for this year.
What to do before the first frost
Zone 6a around Ione 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.
The actual range around Ione's last frost
05/20 is the middle of 30 years of NOAA records, not a promise. Plant by 05/06 and you're betting against frost in roughly 9 years out of 10. 06/04 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Ione compares
Ione's growing season runs about 114 days, ranking 39,367 of 40,283 US ZIP codes measured here, longest to shortest. Within WA, it ranks 663 of 700.
Learn more
zone vs. frost date explains why Zone 6a and Ione's frost date answer different questions, and the frost range explains how to read the range around Ione's dates instead of trusting one.