St. Michael, AK 99659 Frost Dates
99659, near St. Michael, AK: the frost window
Around 06/05 is the usual last spring frost, about 281 days away. Fall's first freeze usually shows up around 09/03, roughly 88 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts St. Michael in Zone 3b (-35 to -30°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
St. Michael's growing season runs out in roughly 1 week — 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
06/05 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/20 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/26 and only about 1 year in 10 sees frost after that.
St. Michael against the rest of the dataset
St. Michael's growing season runs about 88 days, ranking 39,957 of 40,283 US ZIP codes measured here, longest to shortest. Within AK, it ranks 232 of 269.
Learn more
Two guides worth reading on 99659: zone vs. frost date, on why Zone 3b and St. Michael's frost date answer different questions, and the frost range, on how to read the range around St. Michael's dates instead of trusting one.