Carrington, ND 58421 Frost Dates
58421, near Carrington, ND: the frost window
Around 05/10 is the usual last spring frost, about 255 days away. Fall's first freeze usually shows up around 09/28, roughly 139 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Carrington in Zone 4a (-30 to -25°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
Carrington'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 05/10 isn't a guarantee
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 05/23 and only about 1 year in 10 sees frost after that.
Carrington against the rest of the dataset
At roughly 139 frost-free days, Carrington places 37,234 of 40,283 ZIP codes in this dataset. Within ND, it ranks 136 of 405.
Learn more
Two guides worth reading on 58421: zone vs. frost date, on why Zone 4a and Carrington's frost date answer different questions, and the frost range, on how to read the range around Carrington's dates instead of trusting one.