Dawson, ND 58428 Frost Dates
58428, near Dawson, ND: the frost window
Typically, the last spring freeze lands around 05/15, roughly 260 days out. Fall's first freeze usually shows up around 09/25, roughly 133 days after the last spring frost.
Dawson 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
Dawson'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 05/15 isn't a guarantee
05/15 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/04 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/28 and only about 1 year in 10 sees frost after that.
Dawson against the rest of the dataset
At roughly 133 frost-free days, Dawson places 38,152 of 40,283 ZIP codes in this dataset. Within ND, it ranks 294 of 405.
Learn more
Two guides worth reading on 58428: local microclimates, on what one yard in Dawson can differ from the 58428 normal, and zone vs. frost date, on why Zone 4a and Dawson's frost date answer different questions.