Gustavus, AK 99850 Frost Dates
99850, near Gustavus, AK: the frost window
The last spring frost here typically falls around 05/28, about 273 days from today. Fall's first freeze usually shows up around 09/25, roughly 116 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Gustavus in Zone 7a (0 to 5°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
Gustavus'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.
Why 05/28 isn't a guarantee
05/28 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/12 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/12 and only about 1 year in 10 sees frost after that.
Gustavus against the rest of the dataset
Gustavus's growing season runs about 116 days, ranking 39,287 of 40,283 US ZIP codes measured here, longest to shortest. Within AK, it ranks 143 of 269.
Learn more
Two guides worth reading on 99850: the frost range, on how to read the range around Gustavus's dates instead of trusting one, and local microclimates, on what one yard in Gustavus can differ from the 99850 normal.