Nondalton, AK 99640 Frost Dates
99640, near Nondalton, AK: the frost window
Typically, the last spring freeze lands around 05/10, roughly 255 days out. Fall's first freeze usually shows up around 10/01, roughly 144 days after the last spring frost.
Nondalton sits in USDA Zone 4a (-30 to -25°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
Stretching the season past the first frost
Nondalton's growing season runs out in roughly 5 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 Nondalton's last frost
05/10 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/28 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/25 and only about 1 year in 10 sees frost after that.
Nondalton against the rest of the dataset
At roughly 144 frost-free days, Nondalton places 36,476 of 40,283 ZIP codes in this dataset. Within AK, it ranks 64 of 269.
Learn more
Two guides worth reading on 99640: zone vs. frost date, on why Zone 4a and Nondalton's frost date answer different questions, and the frost range, on how to read the range around Nondalton's dates instead of trusting one.