Saint John, ND frost dates
Last spring frostMay 19median date
First fall frostSep 24median date
Growing season128 daysfrost-free
Hardiness zone3bZone 3b
How Saint John compares
- In 8 years out of 10, the last spring frost in Saint John falls between May 5 and June 1, a 27-day window. The first fall frost falls between September 10 and October 5.
- The median last frost is 7 days later than the North Dakota median of May 12.
- Its 128-day growing season is longer than 11% of the 372 North Dakota places with a regular frost season (state median 139 days).
- The last frost is typical for zone 3b, where the median is May 17.
- The weather station records an average of 209 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 5 |
| 50% (median) | May 19 |
| 10% (safe for tender plants) | June 1 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 10 |
| 50% (median) | September 24 |
| 90% (late) | October 5 |
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 Saint John, ND
Saint John, ND frost dates — last frost May 19, first frost Sep 24, zone 3b. whenisthelastfrost.com
Crop
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Start indoors: Feb 24 to Mar 10Transplant outside: Apr 21 to May 5
Start indoors: Mar 10 to Mar 24Transplant outside: Jun 2 to Jun 16
Start indoors: Mar 10 to Mar 24Transplant outside: Jun 2 to Jun 16
Start indoors: Mar 24 to Apr 7Transplant outside: May 26 to Jun 9
Start indoors: Mar 24 to Apr 7Transplant outside: Apr 28 to May 12Sow outdoors: Apr 21 to May 26Plant for fall: Jul 30 to Aug 27
Start indoors: Mar 24 to Apr 7Transplant outside: Apr 21 to May 5Sow outdoors: Apr 21 to May 5Plant for fall: Jul 16 to Aug 6
Start indoors: Mar 24 to Apr 7Transplant outside: May 5 to May 19Plant for fall: Jun 18 to Jul 9
Start indoors: Mar 24 to Apr 7Transplant outside: Apr 28 to May 12Plant for fall: Jun 18 to Jul 9
Start indoors: Mar 24 to Apr 7Transplant outside: May 5 to May 19Plant for fall: Jun 18 to Jul 9
Start indoors: Apr 7 to Apr 21Transplant outside: Jun 9 to Jun 23Sow outdoors: Jun 9 to Jun 23
Start indoors: Apr 7 to Apr 21Transplant outside: May 26 to Jun 9
Sow outdoors: Apr 7 to Apr 28Plant for fall: Jul 2 to Jul 23
Sow outdoors: Apr 7 to Apr 28Plant for fall: Jul 30 to Aug 20
Sow outdoors: Apr 14 to May 26Plant for fall: Aug 13 to Sep 3
Start indoors: Apr 21 to Apr 28Transplant outside: Jun 2 to Jun 9Sow outdoors: May 26 to Jun 9Plant for fall: Jul 9 to Jul 23
Start indoors: Apr 21 to Apr 28Sow outdoors: May 26 to Jun 9Plant for fall: Jul 16 to Jul 30
Start indoors: Apr 21 to Apr 28Sow outdoors: May 26 to Jun 9
Start indoors: Apr 21 to Apr 28Transplant outside: Jun 2 to Jun 16
Sow outdoors: Apr 28 to May 26Plant for fall: Jul 2 to Jul 16
Sow outdoors: Apr 28 to May 26Plant for fall: Jul 16 to Jul 30
Sow outdoors: Apr 28 to May 19
Sow outdoors: May 5 to Jun 2Plant for fall: Jul 16 to Jul 30
Sow outdoors: May 5 to May 26Plant for fall: Jul 30 to Aug 20
Sow outdoors: May 26 to Jun 16Plant for fall: Jul 9 to Jul 23
Sow outdoors: May 26 to Jun 9
Transplant outside: Jun 2 to Jun 23
Plant for fall: Sep 10 to Oct 15
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Saint John, ND
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 24 – Mar 10 | Apr 21 – May 5 | — | — |
| Peppers | Mar 10 – Mar 24 | Jun 2 – Jun 16 | — | — |
| Eggplant | Mar 10 – Mar 24 | Jun 2 – Jun 16 | — | — |
| Tomatoes | Mar 24 – Apr 7 | May 26 – Jun 9 | — | — |
| Lettuce | Mar 24 – Apr 7 | Apr 28 – May 12 | Apr 21 – May 26 | Jul 30 – Aug 27 |
| Kale | Mar 24 – Apr 7 | Apr 21 – May 5 | Apr 21 – May 5 | Jul 16 – Aug 6 |
| Broccoli | Mar 24 – Apr 7 | May 5 – May 19 | — | Jun 18 – Jul 9 |
| Cabbage | Mar 24 – Apr 7 | Apr 28 – May 12 | — | Jun 18 – Jul 9 |
| Cauliflower | Mar 24 – Apr 7 | May 5 – May 19 | — | Jun 18 – Jul 9 |
| Okra | Apr 7 – Apr 21 | Jun 9 – Jun 23 | Jun 9 – Jun 23 | — |
| Basil | Apr 7 – Apr 21 | May 26 – Jun 9 | — | — |
| Peas | — | — | Apr 7 – Apr 28 | Jul 2 – Jul 23 |
| Spinach | — | — | Apr 7 – Apr 28 | Jul 30 – Aug 20 |
| Radishes | — | — | Apr 14 – May 26 | Aug 13 – Sep 3 |
| Cucumbers | Apr 21 – Apr 28 | Jun 2 – Jun 9 | May 26 – Jun 9 | Jul 9 – Jul 23 |
| Zucchini & Summer Squash | Apr 21 – Apr 28 | — | May 26 – Jun 9 | Jul 16 – Jul 30 |
| Winter Squash & Pumpkins | Apr 21 – Apr 28 | — | May 26 – Jun 9 | — |
| Melons & Watermelon | Apr 21 – Apr 28 | Jun 2 – Jun 16 | — | — |
| Carrots | — | — | Apr 28 – May 26 | Jul 2 – Jul 16 |
| Beets | — | — | Apr 28 – May 26 | Jul 16 – Jul 30 |
| Potatoes | — | — | Apr 28 – May 19 | — |
| Swiss Chard | — | — | May 5 – Jun 2 | Jul 16 – Jul 30 |
| Cilantro | — | — | May 5 – May 26 | Jul 30 – Aug 20 |
| Green Beans | — | — | May 26 – Jun 16 | Jul 9 – Jul 23 |
| Sweet Corn | — | — | May 26 – Jun 9 | — |
| Sweet Potatoes | — | Jun 2 – Jun 23 | — | — |
| Garlic | — | — | — | Sep 10 – Oct 15 |
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 Belcourt Keya Radio, ND weather station, 11 km away (elevation 1,959 ft (597 m)).
Frost dates near Saint John
- Belcourt May 19 · Sep 24
- Rolla May 20 · Sep 26
- Dunseith May 19 · Sep 24
- Hansboro May 20 · Sep 26
- Rolette May 22 · Sep 20
- Perth May 20 · Sep 26
- Mylo May 22 · Sep 20
- Agate May 22 · Sep 20
- Rocklake May 18 · Sep 23
- Bisbee May 22 · Sep 20
Frequently asked questions
When is the last frost in Saint John, ND?
The median last spring frost in Saint John, ND is May 19. There is still about a 10% chance of frost after June 1, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Saint John, ND?
The median first fall frost is September 24, with about a 10% chance of frost before September 10.
How long is the growing season in Saint John, ND?
About 128 days between the median last spring frost and first fall frost.
What planting zone is Saint John, ND?
Saint John, ND is in USDA hardiness zone 3b.