FrostDateCheck

Pasco, WA 99323 Frost Dates

When can you plant in Pasco, WA?

Zone 7a

Around 04/07 is the usual last spring frost, about 222 days away. The first fall frost typically arrives around 10/22, about 199 frost-free days later.

The USDA Plant Hardiness Zone Map puts Pasco 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 8 weeks of growing season left in Pasco 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

04/07 is the middle of 30 years of NOAA records, not a promise. Plant by 03/20 and you're betting against frost in roughly 9 years out of 10. 04/30 is the safer bet, historically only a 1-in-10 chance of frost that late.

How Pasco compares

Pasco's growing season runs about 199 days, ranking 18,003 of 40,283 US ZIP codes measured here, longest to shortest. Within WA, it ranks 334 of 700.

Learn more

local microclimates covers what one yard in Pasco can differ from the 99323 normal. zone vs. frost date covers why Zone 7a and Pasco's frost date answer different questions.