Sanborn, ND 58481 Frost Dates
Sanborn, ND: when does the frost end?
The last spring frost here typically falls around 05/11, about 256 days from today. Fall's first freeze usually shows up around 09/28, roughly 138 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Sanborn in Zone 4a (-30 to -25°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
With roughly 4 weeks until Sanborn's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
Why 05/11 isn't a guarantee
05/11 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 05/24 and only about 1 year in 10 sees frost after that.
Sanborn against the rest of the dataset
At roughly 138 frost-free days, Sanborn places 37,467 of 40,283 ZIP codes in this dataset. Within ND, it ranks 198 of 405.
Learn more
Before leaning on 58481's figures: the frost range explains how to read the range around Sanborn's dates instead of trusting one, while local microclimates explains what one yard in Sanborn can differ from the 58481 normal.