Frost dates for 58505 — Bismarck, ND
Last spring frostMay 10median date
First fall frostSep 30median date
Growing season143 daysfrost-free
Hardiness zone4aZone 4a
How Bismarck compares
- In 8 years out of 10, the last spring frost in Bismarck falls between April 30 and May 23, a 23-day window. The first fall frost falls between September 16 and October 13.
- The median last frost is 2 days earlier than the North Dakota median of May 12.
- Its 143-day growing season is longer than 74% of the 372 North Dakota places with a regular frost season (state median 139 days).
- The last frost is typical for zone 4a, where the median is May 12.
- The weather station records an average of 181 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 30 |
| 50% (median) | May 10 |
| 10% (safe for tender plants) | May 23 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 16 |
| 50% (median) | September 30 |
| 90% (late) | October 13 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Bismarck, ND
Frost dates for 58505 — Bismarck, ND — last frost May 10, first frost Sep 30, zone 4a. whenisthelastfrost.com
Crop
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Start indoors: Feb 15 to Mar 1Transplant outside: Apr 12 to Apr 26
Start indoors: Mar 1 to Mar 15Transplant outside: May 24 to Jun 7
Start indoors: Mar 1 to Mar 15Transplant outside: May 24 to Jun 7
Start indoors: Mar 15 to Mar 29Transplant outside: May 17 to May 31
Start indoors: Mar 15 to Mar 29Transplant outside: Apr 19 to May 3Sow outdoors: Apr 12 to May 17Plant for fall: Aug 5 to Sep 2
Start indoors: Mar 15 to Mar 29Transplant outside: Apr 12 to Apr 26Sow outdoors: Apr 12 to Apr 26Plant for fall: Jul 22 to Aug 12
Start indoors: Mar 15 to Mar 29Transplant outside: Apr 26 to May 10Plant for fall: Jun 24 to Jul 15
Start indoors: Mar 15 to Mar 29Transplant outside: Apr 19 to May 3Plant for fall: Jun 24 to Jul 15
Start indoors: Mar 15 to Mar 29Transplant outside: Apr 26 to May 10Plant for fall: Jun 24 to Jul 15
Start indoors: Mar 29 to Apr 12Transplant outside: May 31 to Jun 14Sow outdoors: May 31 to Jun 14
Start indoors: Mar 29 to Apr 12Transplant outside: May 17 to May 31
Sow outdoors: Mar 29 to Apr 19Plant for fall: Jul 8 to Jul 29
Sow outdoors: Mar 29 to Apr 19Plant for fall: Aug 5 to Aug 26
Sow outdoors: Apr 5 to May 17Plant for fall: Aug 19 to Sep 9
Start indoors: Apr 12 to Apr 19Transplant outside: May 24 to May 31Sow outdoors: May 17 to May 31Plant for fall: Jul 15 to Jul 29
Start indoors: Apr 12 to Apr 19Sow outdoors: May 17 to May 31Plant for fall: Jul 22 to Aug 5
Start indoors: Apr 12 to Apr 19Sow outdoors: May 17 to May 31
Start indoors: Apr 12 to Apr 19Transplant outside: May 24 to Jun 7
Sow outdoors: Apr 19 to May 17Plant for fall: Jul 8 to Jul 22
Sow outdoors: Apr 19 to May 17Plant for fall: Jul 22 to Aug 5
Sow outdoors: Apr 19 to May 10
Sow outdoors: Apr 26 to May 24Plant for fall: Jul 22 to Aug 5
Sow outdoors: Apr 26 to May 17Plant for fall: Aug 5 to Aug 26
Sow outdoors: May 17 to Jun 7Plant for fall: Jul 15 to Jul 29
Sow outdoors: May 17 to May 31
Transplant outside: May 24 to Jun 14
Plant for fall: Sep 16 to Oct 21
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Bismarck, ND
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 15 – Mar 1 | Apr 12 – Apr 26 | — | — |
| Peppers | Mar 1 – Mar 15 | May 24 – Jun 7 | — | — |
| Eggplant | Mar 1 – Mar 15 | May 24 – Jun 7 | — | — |
| Tomatoes | Mar 15 – Mar 29 | May 17 – May 31 | — | — |
| Lettuce | Mar 15 – Mar 29 | Apr 19 – May 3 | Apr 12 – May 17 | Aug 5 – Sep 2 |
| Kale | Mar 15 – Mar 29 | Apr 12 – Apr 26 | Apr 12 – Apr 26 | Jul 22 – Aug 12 |
| Broccoli | Mar 15 – Mar 29 | Apr 26 – May 10 | — | Jun 24 – Jul 15 |
| Cabbage | Mar 15 – Mar 29 | Apr 19 – May 3 | — | Jun 24 – Jul 15 |
| Cauliflower | Mar 15 – Mar 29 | Apr 26 – May 10 | — | Jun 24 – Jul 15 |
| Okra | Mar 29 – Apr 12 | May 31 – Jun 14 | May 31 – Jun 14 | — |
| Basil | Mar 29 – Apr 12 | May 17 – May 31 | — | — |
| Peas | — | — | Mar 29 – Apr 19 | Jul 8 – Jul 29 |
| Spinach | — | — | Mar 29 – Apr 19 | Aug 5 – Aug 26 |
| Radishes | — | — | Apr 5 – May 17 | Aug 19 – Sep 9 |
| Cucumbers | Apr 12 – Apr 19 | May 24 – May 31 | May 17 – May 31 | Jul 15 – Jul 29 |
| Zucchini & Summer Squash | Apr 12 – Apr 19 | — | May 17 – May 31 | Jul 22 – Aug 5 |
| Winter Squash & Pumpkins | Apr 12 – Apr 19 | — | May 17 – May 31 | — |
| Melons & Watermelon | Apr 12 – Apr 19 | May 24 – Jun 7 | — | — |
| Carrots | — | — | Apr 19 – May 17 | Jul 8 – Jul 22 |
| Beets | — | — | Apr 19 – May 17 | Jul 22 – Aug 5 |
| Potatoes | — | — | Apr 19 – May 10 | — |
| Swiss Chard | — | — | Apr 26 – May 24 | Jul 22 – Aug 5 |
| Cilantro | — | — | Apr 26 – May 17 | Aug 5 – Aug 26 |
| Green Beans | — | — | May 17 – Jun 7 | Jul 15 – Jul 29 |
| Sweet Corn | — | — | May 17 – May 31 | — |
| Sweet Potatoes | — | May 24 – Jun 14 | — | — |
| Garlic | — | — | — | Sep 16 – Oct 21 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Bismarck 2.4 Nnw, ND weather station, 2 km away (elevation 1,831 ft (558 m)).
ZIP codes in Bismarck: 58501 58502 58503 58504 58505 58506 58507
Frost dates near Bismarck
- Mandan May 13 · Sep 27
- Baldwin May 10 · Sep 30
- Menoken May 14 · Sep 30
- Saint Anthony May 14 · Sep 27
- Sterling May 11 · Sep 29
- Wilton May 11 · Sep 30
- Moffit May 11 · Sep 29
- Regan May 11 · Sep 30
Frequently asked questions
When is the last frost in Bismarck, ND?
The median last spring frost in Bismarck, ND is May 10. There is still about a 10% chance of frost after May 23, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Bismarck, ND?
The median first fall frost is September 30, with about a 10% chance of frost before September 16.
How long is the growing season in Bismarck, ND?
About 143 days between the median last spring frost and first fall frost.
What planting zone is Bismarck, ND?
Bismarck, ND is in USDA hardiness zone 4a.