When to plant in Bismarck, ND
USDA Zone 4aBismarck, North Dakota frost dates, USDA zone, and a full-year planting calendar, drawn from the nearest NOAA station and tuned to the local season.
In zone 4a, Bismarck winters are severe; choose cold-hardy perennials and time annuals carefully around the frost dates above.
Frost probability
BISMARCK 2.4 NNW · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Bismarck’s own odds, recorded at BISMARCK 2.4 NNW.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | Jun 2 | May 20 | May 8 | Sep 8 | Sep 21 | Oct 4 |
| 32°F | May 23 | May 10 | Apr 30 | Sep 16 | Sep 30 | Oct 13 |
| 28°F | May 13 | May 1 | Apr 18 | Sep 25 | Oct 9 | Oct 22 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Bismarck, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 5 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Bismarck planting FAQ
When is the last spring frost in Bismarck, ND?
Plan for the last spring frost in Bismarck around May 10 (the date it has a 50% chance of a 32°F freeze). Anything frost-sensitive should go out after it.
When is the first fall frost in Bismarck, ND?
In Bismarck, the first 32°F freeze of fall lands around September 30 on average. Time your last harvests and any season-extension cover before it.
What hardiness zone is Bismarck in?
Bismarck is in USDA hardiness zone 4a. In zone 4a, winters are cold — pick cold-hardy varieties and protect tender crops.
How long is the growing season in Bismarck?
Bismarck has about 143 frost-free days — a short growing season — between the average last spring frost (May 10) and first fall frost (September 30).
When should I plant tomatoes in Bismarck?
For Bismarck, sow tomatoes indoors about March 15–March 29 and move the seedlings out around May 17, after the last spring frost.
Never miss a window in Bismarck
An email when it’s time to start seeds, transplant, and sow — timed to Bismarck’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reachFrost dates recorded at BISMARCK 2.4 NNW, 3 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Bismarck, ND — Frost Dates & Zone 4a." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00320817. Retrieved from https://blissgarden.com/north-dakota/bismarck.