Berlin, ND 58415 Frost Dates
58415, near Berlin, 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 140 days after the last spring frost.
Berlin sits in USDA Zone 4b (-25 to -20°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
Berlin'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 05/22 and only about 1 year in 10 sees frost after that.
Berlin against the rest of the dataset
Berlin's growing season runs about 140 days, ranking 37,200 of 40,283 US ZIP codes measured here, longest to shortest. Within ND, it ranks 133 of 405.
Learn more
Two guides worth reading on 58415: zone vs. frost date, on why Zone 4b and Berlin's frost date answer different questions, and the frost range, on how to read the range around Berlin's dates instead of trusting one.