Bismarck, ND Frost Dates
The last spring frost in Bismarck usually comes around May 14 and the first fall frost around September 27.
| Spring (last) | Fall (first) | |
|---|---|---|
| Frost, 32°F | May 14 | September 27 |
| Hard freeze, 28°F | May 3 | October 5 |
Growing season: about 136 days.
Frequently asked questions
When is the last frost in Bismarck, ND?
The median date of the last spring frost (32°F) is May 14. In half of years the last frost comes earlier and in half it comes later, so waiting a week or two past May 14 lowers the risk for tender plants.
When is the first frost in Bismarck?
The median date of the first fall frost (32°F) is September 27, and a hard freeze (28°F) usually follows around October 5.
How long is the growing season in Bismarck?
About 136 days between the median last spring frost and first fall frost.
NOAA NCEI U.S. Climate Normals 1991-2020, station USW00024011. Median (50% probability) dates. Low spots and valleys can frost later in spring and earlier in fall than the station.