Airway Heights, WA 99001 Frost Dates
99001, near Airway Heights, WA: the frost window
Around 05/10 is the usual last spring frost, about 255 days away. Fall's first freeze usually shows up around 09/26, roughly 137 days after the last spring frost.
Airway Heights sits in USDA Zone 6b (-5 to 0°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.
Stretching the season past the first frost
Airway Heights's growing season runs out in roughly 4 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
Why 05/10 isn't a guarantee
05/10 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/25 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/30 and only about 1 year in 10 sees frost after that.
Airway Heights against the rest of the dataset
About 137 days separate Airway Heights's last and first frost, putting it 37,496 of 40,283 ZIP codes nationally. Within WA, it ranks 618 of 700.
Learn more
Two guides worth reading on 99001: local microclimates, on what one yard in Airway Heights can differ from the 99001 normal, and zone vs. frost date, on why Zone 6b and Airway Heights's frost date answer different questions.