Zap, ND 58580 Frost Dates
58580, near Zap, ND: the frost window
Around 05/21 is the usual last spring frost, about 266 days away. Fall's first freeze usually shows up around 09/20, roughly 121 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 Zap, not a forecast for this year.
Stretching the season past the first frost
Zap's growing season runs out in roughly 3 weeks — a cold frame or greenhouse kit is the usual way to keep cool-weather crops going past the first frost.
How much risk comes with planting early here
05/21 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/07 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/03 and only about 1 year in 10 sees frost after that.
Zap against the rest of the dataset
About 121 days separate Zap's last and first frost, putting it 39,052 of 40,283 ZIP codes nationally. Within ND, it ranks 384 of 405.
Learn more
Two guides worth reading on 58580: zone vs. frost date, on why Zone 4a and Zap's frost date answer different questions, and the frost range, on how to read the range around Zap's dates instead of trusting one.