Fairbanks, AK 99709 Frost Dates
99709, near Fairbanks, AK: the frost window
Around 05/16 is the usual last spring frost, about 261 days away. Fall's first freeze usually shows up around 09/08, roughly 114 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Fairbanks 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
Fairbanks's growing season runs out in roughly 2 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 Fairbanks's last frost
05/16 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/05 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.
Fairbanks against the rest of the dataset
Fairbanks's growing season runs about 114 days, ranking 39,350 of 40,283 US ZIP codes measured here, longest to shortest. Within AK, it ranks 145 of 269.
Learn more
Two guides worth reading on 99709: the frost range, on how to read the range around Fairbanks's dates instead of trusting one, and local microclimates, on what one yard in Fairbanks can differ from the 99709 normal.