Delta Junction, AK 99731 Frost Dates
Frost dates for Delta Junction, AK, ZIP 99731
Typically, the last spring freeze lands around 05/17, roughly 262 days out. The first fall frost typically arrives around 09/07, about 113 frost-free days later.
Zone 2a (-50 to -45°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 Delta Junction, not a forecast for this year.
What to do before the first frost
Zone 2a around Delta Junction has about 1 week left before the first fall frost — that's the usual window to get a cold frame up if you want to keep harvesting past it.
The actual range around Delta Junction's last frost
05/17 is the middle of 30 years of NOAA records, not a promise. Plant by 05/03 and you're betting against frost in roughly 9 years out of 10. 05/31 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Delta Junction compares
At roughly 113 frost-free days, Delta Junction places 39,398 of 40,283 ZIP codes in this dataset. Within AK, it ranks 147 of 269.
Learn more
local microclimates explains what one yard in Delta Junction can differ from the 99731 normal, and zone vs. frost date explains why Zone 2a and Delta Junction's frost date answer different questions.