South Prairie, WA 98385 Frost Dates
98385, near South Prairie, WA: the frost window
Typically, the last spring freeze lands around 04/07, roughly 222 days out. Fall's first freeze usually shows up around 10/30, roughly 204 days after the last spring frost.
South Prairie sits in USDA Zone 8b (15 to 20°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
South Prairie'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.
How much risk comes with planting early here
04/07 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 03/16 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 04/27 and only about 1 year in 10 sees frost after that.
South Prairie against the rest of the dataset
South Prairie's growing season runs about 204 days, ranking 16,746 of 40,283 US ZIP codes measured here, longest to shortest. Within WA, it ranks 284 of 700.
Learn more
Two guides worth reading on 98385: zone vs. frost date, on why Zone 8b and South Prairie's frost date answer different questions, and the frost range, on how to read the range around South Prairie's dates instead of trusting one.