Williston, ND 58802 Frost Dates
When can you plant in Williston, ND?
Around 05/21 is the usual last spring frost, about 266 days away. The first fall frost typically arrives around 09/21, about 123 frost-free days later.
Williston sits in USDA Zone 4a (-30 to -25°F average annual minimum). The dates above are NOAA's 1991-2020 normal at the nearest reporting station, a 30-year average, not a forecast.
What to do before the first frost
About 3 weeks of growing season left in Williston before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
Why 05/21 isn't a guarantee
05/21 is the middle of 30 years of NOAA records, not a promise. Plant by 05/08 and you're betting against frost in roughly 9 years out of 10. 06/03 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Williston compares
Williston's growing season runs about 123 days, ranking 38,881 of 40,283 US ZIP codes measured here, longest to shortest. Within ND, it ranks 372 of 405.
Learn more
the frost range covers how to read the range around Williston's dates instead of trusting one. local microclimates covers what one yard in Williston can differ from the 58802 normal.