Washburn, ND frost dates
Last spring frostMay 12median date
First fall frostSep 30median date
Growing season141 daysfrost-free
Hardiness zone4aZone 4a
How Washburn compares
- In 8 years out of 10, the last spring frost in Washburn falls between April 30 and May 25, a 25-day window. The first fall frost falls between September 18 and October 11.
- The median last frost is the same as the North Dakota median of May 12.
- Its 141-day growing season is longer than 63% 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 182 nights a year at or below 32°F.
- Compared with Bismarck, ND, 59 km away, the last frost here is 2 days later than there and the growing season is 2 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 30 |
| 50% (median) | May 12 |
| 10% (safe for tender plants) | May 25 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 18 |
| 50% (median) | September 30 |
| 90% (late) | October 11 |
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 Washburn, ND
Washburn, ND frost dates — last frost May 12, first frost Sep 30, zone 4a. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Feb 17 to Mar 3Transplant outside: Apr 14 to Apr 28
Start indoors: Mar 3 to Mar 17Transplant outside: May 26 to Jun 9
Start indoors: Mar 3 to Mar 17Transplant outside: May 26 to Jun 9
Start indoors: Mar 17 to Mar 31Transplant outside: May 19 to Jun 2
Start indoors: Mar 17 to Mar 31Transplant outside: Apr 21 to May 5Sow outdoors: Apr 14 to May 19Plant for fall: Aug 5 to Sep 2
Start indoors: Mar 17 to Mar 31Transplant outside: Apr 14 to Apr 28Sow outdoors: Apr 14 to Apr 28Plant for fall: Jul 22 to Aug 12
Start indoors: Mar 17 to Mar 31Transplant outside: Apr 28 to May 12Plant for fall: Jun 24 to Jul 15
Start indoors: Mar 17 to Mar 31Transplant outside: Apr 21 to May 5Plant for fall: Jun 24 to Jul 15
Start indoors: Mar 17 to Mar 31Transplant outside: Apr 28 to May 12Plant for fall: Jun 24 to Jul 15
Start indoors: Mar 31 to Apr 14Transplant outside: Jun 2 to Jun 16Sow outdoors: Jun 2 to Jun 16
Start indoors: Mar 31 to Apr 14Transplant outside: May 19 to Jun 2
Sow outdoors: Mar 31 to Apr 21Plant for fall: Jul 8 to Jul 29
Sow outdoors: Mar 31 to Apr 21Plant for fall: Aug 5 to Aug 26
Sow outdoors: Apr 7 to May 19Plant for fall: Aug 19 to Sep 9
Start indoors: Apr 14 to Apr 21Transplant outside: May 26 to Jun 2Sow outdoors: May 19 to Jun 2Plant for fall: Jul 15 to Jul 29
Start indoors: Apr 14 to Apr 21Sow outdoors: May 19 to Jun 2Plant for fall: Jul 22 to Aug 5
Start indoors: Apr 14 to Apr 21Sow outdoors: May 19 to Jun 2
Start indoors: Apr 14 to Apr 21Transplant outside: May 26 to Jun 9
Sow outdoors: Apr 21 to May 19Plant for fall: Jul 8 to Jul 22
Sow outdoors: Apr 21 to May 19Plant for fall: Jul 22 to Aug 5
Sow outdoors: Apr 21 to May 12
Sow outdoors: Apr 28 to May 26Plant for fall: Jul 22 to Aug 5
Sow outdoors: Apr 28 to May 19Plant for fall: Aug 5 to Aug 26
Sow outdoors: May 19 to Jun 9Plant for fall: Jul 15 to Jul 29
Sow outdoors: May 19 to Jun 2
Transplant outside: May 26 to Jun 16
Plant for fall: Sep 16 to Oct 21
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Washburn, ND
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 17 – Mar 3 | Apr 14 – Apr 28 | — | — |
| Peppers | Mar 3 – Mar 17 | May 26 – Jun 9 | — | — |
| Eggplant | Mar 3 – Mar 17 | May 26 – Jun 9 | — | — |
| Tomatoes | Mar 17 – Mar 31 | May 19 – Jun 2 | — | — |
| Lettuce | Mar 17 – Mar 31 | Apr 21 – May 5 | Apr 14 – May 19 | Aug 5 – Sep 2 |
| Kale | Mar 17 – Mar 31 | Apr 14 – Apr 28 | Apr 14 – Apr 28 | Jul 22 – Aug 12 |
| Broccoli | Mar 17 – Mar 31 | Apr 28 – May 12 | — | Jun 24 – Jul 15 |
| Cabbage | Mar 17 – Mar 31 | Apr 21 – May 5 | — | Jun 24 – Jul 15 |
| Cauliflower | Mar 17 – Mar 31 | Apr 28 – May 12 | — | Jun 24 – Jul 15 |
| Okra | Mar 31 – Apr 14 | Jun 2 – Jun 16 | Jun 2 – Jun 16 | — |
| Basil | Mar 31 – Apr 14 | May 19 – Jun 2 | — | — |
| Peas | — | — | Mar 31 – Apr 21 | Jul 8 – Jul 29 |
| Spinach | — | — | Mar 31 – Apr 21 | Aug 5 – Aug 26 |
| Radishes | — | — | Apr 7 – May 19 | Aug 19 – Sep 9 |
| Cucumbers | Apr 14 – Apr 21 | May 26 – Jun 2 | May 19 – Jun 2 | Jul 15 – Jul 29 |
| Zucchini & Summer Squash | Apr 14 – Apr 21 | — | May 19 – Jun 2 | Jul 22 – Aug 5 |
| Winter Squash & Pumpkins | Apr 14 – Apr 21 | — | May 19 – Jun 2 | — |
| Melons & Watermelon | Apr 14 – Apr 21 | May 26 – Jun 9 | — | — |
| Carrots | — | — | Apr 21 – May 19 | Jul 8 – Jul 22 |
| Beets | — | — | Apr 21 – May 19 | Jul 22 – Aug 5 |
| Potatoes | — | — | Apr 21 – May 12 | — |
| Swiss Chard | — | — | Apr 28 – May 26 | Jul 22 – Aug 5 |
| Cilantro | — | — | Apr 28 – May 19 | Aug 5 – Aug 26 |
| Green Beans | — | — | May 19 – Jun 9 | Jul 15 – Jul 29 |
| Sweet Corn | — | — | May 19 – Jun 2 | — |
| Sweet Potatoes | — | May 26 – Jun 16 | — | — |
| 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 Washburn, ND weather station, 2 km away (elevation 1,755 ft (535 m)).
Frost dates near Washburn
- Underwood May 10 · Sep 29
- Center May 11 · Sep 29
- Wilton May 11 · Sep 30
- Turtle Lake May 14 · Sep 26
- Stanton May 12 · Oct 3
- Mercer May 14 · Sep 26
- Coleharbor May 10 · Sep 29
- Riverdale May 12 · Oct 3
- Regan May 11 · Sep 30
- Baldwin May 10 · Sep 30
Frequently asked questions
When is the last frost in Washburn, ND?
The median last spring frost in Washburn, ND is May 12. There is still about a 10% chance of frost after May 25, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Washburn, ND?
The median first fall frost is September 30, with about a 10% chance of frost before September 18.
How long is the growing season in Washburn, ND?
About 141 days between the median last spring frost and first fall frost.
What planting zone is Washburn, ND?
Washburn, ND is in USDA hardiness zone 4a.