Gustavus, AK 99840 Frost Dates
When can you plant in Gustavus, AK?
The last spring frost here typically falls around 05/06, about 251 days from today. The first fall frost typically arrives around 10/01, about 146 frost-free days later.
Zone 5a (-20 to -15°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 Gustavus, not a forecast for this year.
What to do before the first frost
About 5 weeks of growing season left in Gustavus before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around Gustavus's last frost
05/06 is the middle of 30 years of NOAA records, not a promise. Plant by 04/24 and you're betting against frost in roughly 9 years out of 10. 05/22 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Gustavus compares
At roughly 146 frost-free days, Gustavus places 36,083 of 40,283 ZIP codes in this dataset. Within AK, it ranks 59 of 269.
Learn more
local microclimates covers what one yard in Gustavus can differ from the 99840 normal. zone vs. frost date covers why Zone 5a and Gustavus's frost date answer different questions.