Carbonado, WA 98430 Frost Dates
98430, near Carbonado, WA: the frost window
Around 04/11 is the usual last spring frost, about 226 days away. Fall's first freeze usually shows up around 10/30, roughly 202 days after the last spring frost.
Zone 8b (15 to 20°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 Carbonado, not a forecast for this year.
Stretching the season past the first frost
Carbonado's growing season runs out in roughly 9 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
The actual range around Carbonado's last frost
04/11 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/23 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/29 and only about 1 year in 10 sees frost after that.
Carbonado against the rest of the dataset
About 202 days separate Carbonado's last and first frost, putting it 17,307 of 40,283 ZIP codes nationally. Within WA, it ranks 308 of 700.
Learn more
Two guides worth reading on 98430: zone vs. frost date, on why Zone 8b and Carbonado's frost date answer different questions, and the frost range, on how to read the range around Carbonado's dates instead of trusting one.