Jamestown, ND 58401 Frost Dates
When can you plant in Jamestown, ND?
Around 05/08 is the usual last spring frost, about 253 days away. The first fall frost typically arrives around 09/29, about 143 frost-free days later.
Zone 4b (-25 to -20°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 Jamestown, not a forecast for this year.
What to do before the first frost
About 5 weeks of growing season left in Jamestown before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around Jamestown's last frost
05/08 is the middle of 30 years of NOAA records, not a promise. Plant by 04/26 and you're betting against frost in roughly 9 years out of 10. 05/21 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Jamestown compares
Jamestown's growing season runs about 143 days, ranking 36,498 of 40,283 US ZIP codes measured here, longest to shortest. Within ND, it ranks 76 of 405.
Learn more
local microclimates covers what one yard in Jamestown can differ from the 58401 normal. zone vs. frost date covers why Zone 4b and Jamestown's frost date answer different questions.