FrostDateCheck

Mandan, ND 58554 Frost Dates

When can you plant in Mandan, ND?

Zone 4a

Around 05/13 is the usual last spring frost, about 258 days away. The first fall frost typically arrives around 09/27, about 136 frost-free days later.

Mandan 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 4 weeks of growing season left in Mandan before the first fall frost — a cold frame or row cover can stretch harvest weeks past that date.

Why 05/13 isn't a guarantee

05/13 is the middle of 30 years of NOAA records, not a promise. Plant by 05/01 and you're betting against frost in roughly 9 years out of 10. 05/26 is the safer bet, historically only a 1-in-10 chance of frost that late.

How Mandan compares

Mandan's growing season runs about 136 days, ranking 37,626 of 40,283 US ZIP codes measured here, longest to shortest. Within ND, it ranks 222 of 405.

Learn more

the frost range covers how to read the range around Mandan's dates instead of trusting one. local microclimates covers what one yard in Mandan can differ from the 58554 normal.