Sultan, WA 98294 Frost Dates
Sultan, WA: when does the frost end?
Typically, the last spring freeze lands around 04/15, roughly 230 days out. Fall's first freeze usually shows up around 10/25, roughly 192 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Sultan in Zone 8b (15 to 20°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
Stretching the season past the first frost
With roughly 8 weeks until Sultan's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
The actual range around Sultan's last frost
04/15 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/25 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/07 and only about 1 year in 10 sees frost after that.
Sultan against the rest of the dataset
About 192 days separate Sultan's last and first frost, putting it 20,255 of 40,283 ZIP codes nationally. Within WA, it ranks 391 of 700.
Learn more
Before leaning on 98294's figures: zone vs. frost date explains why Zone 8b and Sultan's frost date answer different questions, while the frost range explains how to read the range around Sultan's dates instead of trusting one.