Index, WA 98256 Frost Dates
When can you plant in Index, WA?
The last spring frost here typically falls around 04/14, about 229 days from today. The first fall frost typically arrives around 10/29, about 197 frost-free days later.
Index sits in USDA Zone 8a (10 to 15°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
What to do before the first frost
About 9 weeks of growing season left in Index before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 04/14 isn't a guarantee
04/14 is the middle of 30 years of NOAA records, not a promise. Plant by 03/26 and you're betting against frost in roughly 9 years out of 10. 05/04 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Index compares
About 197 days separate Index's last and first frost, putting it 18,846 of 40,283 ZIP codes nationally. Within WA, it ranks 338 of 700.
Learn more
zone vs. frost date covers why Zone 8a and Index's frost date answer different questions. the frost range covers how to read the range around Index's dates instead of trusting one.