Marmarth, ND 58643 Frost Dates
When can you plant in Marmarth, ND?
Around 05/16 is the usual last spring frost, about 261 days away. The first fall frost typically arrives around 09/26, about 132 frost-free days later.
Zone 4a (-30 to -25°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 Marmarth, not a forecast for this year.
What to do before the first frost
About 4 weeks of growing season left in Marmarth before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.
The actual range around Marmarth's last frost
05/16 is the middle of 30 years of NOAA records, not a promise. Plant by 05/04 and you're betting against frost in roughly 9 years out of 10. 05/29 is the safer bet, historically only a 1-in-10 chance of frost that late.
How Marmarth compares
About 132 days separate Marmarth's last and first frost, putting it 38,236 of 40,283 ZIP codes nationally. Within ND, it ranks 302 of 405.
Learn more
zone vs. frost date covers why Zone 4a and Marmarth's frost date answer different questions. the frost range covers how to read the range around Marmarth's dates instead of trusting one.