Des Moines, WA 98198 Frost Dates
Des Moines, WA: when does the frost end?
The last spring frost here typically falls around 03/02, about 186 days from today. Fall's first freeze usually shows up around 11/23, roughly 266 days after the last spring frost.
Zone 9a (20 to 25°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 Des Moines, not a forecast for this year.
Stretching the season past the first frost
With roughly 12 weeks until Des Moines's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
How much risk comes with planting early here
03/02 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 02/05 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 03/23 and only about 1 year in 10 sees frost after that.
Des Moines against the rest of the dataset
Des Moines's growing season runs about 266 days, ranking 5,919 of 40,283 US ZIP codes measured here, longest to shortest. Within WA, it ranks 19 of 700.
Learn more
Before leaning on 98198's figures: the frost range explains how to read the range around Des Moines's dates instead of trusting one, while local microclimates explains what one yard in Des Moines can differ from the 98198 normal.