Crosby, ND 58730 Frost Dates
Crosby, ND: when does the frost end?
Around 05/17 is the usual last spring frost, about 262 days away. Fall's first freeze usually shows up around 09/23, roughly 128 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 Crosby, not a forecast for this year.
Stretching the season past the first frost
With roughly 4 weeks until Crosby's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 05/17 isn't a guarantee
05/17 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/06 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 05/28 and only about 1 year in 10 sees frost after that.
Crosby against the rest of the dataset
Crosby's growing season runs about 128 days, ranking 38,552 of 40,283 US ZIP codes measured here, longest to shortest. Within ND, it ranks 320 of 405.
Learn more
Before leaning on 58730's figures: local microclimates explains what one yard in Crosby can differ from the 58730 normal, while zone vs. frost date explains why Zone 4a and Crosby's frost date answer different questions.