Upham, ND 58713 Frost Dates
58713, near Upham, ND: the frost window
Around 05/15 is the usual last spring frost, about 260 days away. Fall's first freeze usually shows up around 09/25, roughly 132 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Upham in Zone 3b (-35 to -30°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
Upham'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 05/03 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/26 and only about 1 year in 10 sees frost after that.
Upham against the rest of the dataset
At roughly 132 frost-free days, Upham places 38,234 of 40,283 ZIP codes in this dataset. Within ND, it ranks 300 of 405.
Learn more
Two guides worth reading on 58713: local microclimates, on what one yard in Upham can differ from the 58713 normal, and zone vs. frost date, on why Zone 3b and Upham's frost date answer different questions.