Medical Lake, WA 99011 Frost Dates
99011, near Medical Lake, 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.
Zone 6b (-5 to 0°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 Medical Lake, not a forecast for this year.
Stretching the season past the first frost
Medical Lake'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.
The actual range around Medical Lake's last frost
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.
Medical Lake against the rest of the dataset
About 137 days separate Medical Lake's last and first frost, putting it 37,512 of 40,283 ZIP codes nationally. Within WA, it ranks 620 of 700.
Learn more
Two guides worth reading on 99011: local microclimates, on what one yard in Medical Lake can differ from the 99011 normal, and zone vs. frost date, on why Zone 6b and Medical Lake's frost date answer different questions.