Rolla, ND 58316 Frost Dates
58316, near Rolla, ND: the frost window
Around 05/19 is the usual last spring frost, about 264 days away. Fall's first freeze usually shows up around 09/24, roughly 126 days after the last spring frost.
Zone 3b (-35 to -30°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 Rolla, not a forecast for this year.
Stretching the season past the first frost
Rolla'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.
How much risk comes with planting early here
05/19 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/05 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/01 and only about 1 year in 10 sees frost after that.
Rolla against the rest of the dataset
Rolla's growing season runs about 126 days, ranking 38,693 of 40,283 US ZIP codes measured here, longest to shortest. Within ND, it ranks 355 of 405.
Learn more
Two guides worth reading on 58316: zone vs. frost date, on why Zone 3b and Rolla's frost date answer different questions, and the frost range, on how to read the range around Rolla's dates instead of trusting one.