Walla Walla, WA 99362 Frost Dates
When can you plant in Walla Walla, WA?
The last spring frost here typically falls around 03/27, about 211 days from today. The first fall frost typically arrives around 10/31, about 219 frost-free days later.
The USDA Plant Hardiness Zone Map puts Walla Walla in Zone 7a (0 to 5°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 9 weeks of growing season left in Walla Walla before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around Walla Walla's last frost
03/27 is the middle of 30 years of NOAA records, not a promise. Plant by 03/03 and you're betting against frost in roughly 9 years out of 10. 04/22 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Walla Walla compares
About 219 days separate Walla Walla's last and first frost, putting it 12,963 of 40,283 ZIP codes nationally. Within WA, it ranks 239 of 700.
Learn more
zone vs. frost date covers why Zone 7a and Walla Walla's frost date answer different questions. the frost range covers how to read the range around Walla Walla's dates instead of trusting one.