Colfax, ND 58018 Frost Dates
58018, near Colfax, ND: the frost window
The last spring frost here typically falls around 05/06, about 251 days from today. Fall's first freeze usually shows up around 09/29, roughly 145 days after the last spring frost.
Zone 4a (-30 to -25°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 Colfax, not a forecast for this year.
Stretching the season past the first frost
Colfax'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.
Why 05/06 isn't a guarantee
05/06 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 04/24 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/19 and only about 1 year in 10 sees frost after that.
Colfax against the rest of the dataset
At roughly 145 frost-free days, Colfax places 36,290 of 40,283 ZIP codes in this dataset. Within ND, it ranks 61 of 405.
Learn more
Two guides worth reading on 58018: the frost range, on how to read the range around Colfax's dates instead of trusting one, and local microclimates, on what one yard in Colfax can differ from the 58018 normal.