Portland, ND 58274 Frost Dates
When can you plant in Portland, ND?
Typically, the last spring freeze lands around 05/13, roughly 258 days out. The first fall frost typically arrives around 09/27, about 136 frost-free days later.
The USDA Plant Hardiness Zone Map puts Portland in Zone 4a (-30 to -25°F average annual minimum); frost dates are NOAA's 1991-2020 station normal, not this year's forecast.
What to do before the first frost
About 4 weeks of growing season left in Portland before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around Portland's last frost
05/13 is the middle of 30 years of NOAA records, not a promise. Plant by 04/30 and you're betting against frost in roughly 9 years out of 10. 05/25 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Portland compares
About 136 days separate Portland's last and first frost, putting it 37,751 of 40,283 ZIP codes nationally. Within ND, it ranks 233 of 405.
Learn more
local microclimates covers what one yard in Portland can differ from the 58274 normal. zone vs. frost date covers why Zone 4a and Portland's frost date answer different questions.