Williston, ND 58801 Frost Dates
Williston, ND: when does the frost end?
Around 05/21 is the usual last spring frost, about 266 days away. Fall's first freeze usually shows up around 09/21, roughly 123 days after the last spring frost.
The USDA Plant Hardiness Zone Map puts Williston 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 3 weeks until Williston's first fall frost, a row cover or cold frame is what stretches the last few weeks of harvest here.
How much risk comes with planting early here
05/21 is the middle of 30 years of NOAA records, not a promise. Getting tender plants in by 05/08 carries real risk, frost has hit that late in about 9 of 10 years here. Wait until 06/03 and only about 1 year in 10 sees frost after that.
Williston against the rest of the dataset
About 123 days separate Williston's last and first frost, putting it 38,880 of 40,283 ZIP codes nationally. Within ND, it ranks 371 of 405.
Learn more
Before leaning on 58801's figures: the frost range explains how to read the range around Williston's dates instead of trusting one, while local microclimates explains what one yard in Williston can differ from the 58801 normal.