Zahl, ND frost dates
Last spring frostMay 18median date
First fall frostSep 20median date
Growing season125 daysfrost-free
Hardiness zone4aZone 4a
How Zahl compares
- In 8 years out of 10, the last spring frost in Zahl falls between May 6 and May 30, a 24-day window. The first fall frost falls between September 7 and October 1.
- The median last frost is 6 days later than the North Dakota median of May 12.
- Its 125-day growing season is longer than 9% of the 372 North Dakota places with a regular frost season (state median 139 days).
- The last frost is 6 days later than the zone 4a median of May 12. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 4a chart.
- The weather station records an average of 200 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 6 |
| 50% (median) | May 18 |
| 10% (safe for tender plants) | May 30 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 7 |
| 50% (median) | September 20 |
| 90% (late) | October 1 |
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 Zahl, ND
Zahl, ND frost dates — last frost May 18, first frost Sep 20, zone 4a. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Feb 23 to Mar 9Transplant outside: Apr 20 to May 4
Start indoors: Mar 9 to Mar 23Transplant outside: Jun 1 to Jun 15
Start indoors: Mar 9 to Mar 23Transplant outside: Jun 1 to Jun 15
Start indoors: Mar 23 to Apr 6Transplant outside: May 25 to Jun 8
Start indoors: Mar 23 to Apr 6Transplant outside: Apr 27 to May 11Sow outdoors: Apr 20 to May 25Plant for fall: Jul 26 to Aug 23
Start indoors: Mar 23 to Apr 6Transplant outside: Apr 20 to May 4Sow outdoors: Apr 20 to May 4Plant for fall: Jul 12 to Aug 2
Start indoors: Mar 23 to Apr 6Transplant outside: May 4 to May 18Plant for fall: Jun 14 to Jul 5
Start indoors: Mar 23 to Apr 6Transplant outside: Apr 27 to May 11Plant for fall: Jun 14 to Jul 5
Start indoors: Mar 23 to Apr 6Transplant outside: May 4 to May 18Plant for fall: Jun 14 to Jul 5
Start indoors: Apr 6 to Apr 20Transplant outside: Jun 8 to Jun 22Sow outdoors: Jun 8 to Jun 22
Start indoors: Apr 6 to Apr 20Transplant outside: May 25 to Jun 8
Sow outdoors: Apr 6 to Apr 27Plant for fall: Jun 28 to Jul 19
Sow outdoors: Apr 6 to Apr 27Plant for fall: Jul 26 to Aug 16
Sow outdoors: Apr 13 to May 25Plant for fall: Aug 9 to Aug 30
Start indoors: Apr 20 to Apr 27Transplant outside: Jun 1 to Jun 8Sow outdoors: May 25 to Jun 8Plant for fall: Jul 5 to Jul 19
Start indoors: Apr 20 to Apr 27Sow outdoors: May 25 to Jun 8Plant for fall: Jul 12 to Jul 26
Start indoors: Apr 20 to Apr 27Sow outdoors: May 25 to Jun 8
Start indoors: Apr 20 to Apr 27Transplant outside: Jun 1 to Jun 15
Sow outdoors: Apr 27 to May 25Plant for fall: Jun 28 to Jul 12
Sow outdoors: Apr 27 to May 25Plant for fall: Jul 12 to Jul 26
Sow outdoors: Apr 27 to May 18
Sow outdoors: May 4 to Jun 1Plant for fall: Jul 12 to Jul 26
Sow outdoors: May 4 to May 25Plant for fall: Jul 26 to Aug 16
Sow outdoors: May 25 to Jun 15Plant for fall: Jul 5 to Jul 19
Sow outdoors: May 25 to Jun 8
Transplant outside: Jun 1 to Jun 22
Plant for fall: Sep 6 to Oct 11
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Zahl, ND
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 23 – Mar 9 | Apr 20 – May 4 | — | — |
| Peppers | Mar 9 – Mar 23 | Jun 1 – Jun 15 | — | — |
| Eggplant | Mar 9 – Mar 23 | Jun 1 – Jun 15 | — | — |
| Tomatoes | Mar 23 – Apr 6 | May 25 – Jun 8 | — | — |
| Lettuce | Mar 23 – Apr 6 | Apr 27 – May 11 | Apr 20 – May 25 | Jul 26 – Aug 23 |
| Kale | Mar 23 – Apr 6 | Apr 20 – May 4 | Apr 20 – May 4 | Jul 12 – Aug 2 |
| Broccoli | Mar 23 – Apr 6 | May 4 – May 18 | — | Jun 14 – Jul 5 |
| Cabbage | Mar 23 – Apr 6 | Apr 27 – May 11 | — | Jun 14 – Jul 5 |
| Cauliflower | Mar 23 – Apr 6 | May 4 – May 18 | — | Jun 14 – Jul 5 |
| Okra | Apr 6 – Apr 20 | Jun 8 – Jun 22 | Jun 8 – Jun 22 | — |
| Basil | Apr 6 – Apr 20 | May 25 – Jun 8 | — | — |
| Peas | — | — | Apr 6 – Apr 27 | Jun 28 – Jul 19 |
| Spinach | — | — | Apr 6 – Apr 27 | Jul 26 – Aug 16 |
| Radishes | — | — | Apr 13 – May 25 | Aug 9 – Aug 30 |
| Cucumbers | Apr 20 – Apr 27 | Jun 1 – Jun 8 | May 25 – Jun 8 | Jul 5 – Jul 19 |
| Zucchini & Summer Squash | Apr 20 – Apr 27 | — | May 25 – Jun 8 | Jul 12 – Jul 26 |
| Winter Squash & Pumpkins | Apr 20 – Apr 27 | — | May 25 – Jun 8 | — |
| Melons & Watermelon | Apr 20 – Apr 27 | Jun 1 – Jun 15 | — | — |
| Carrots | — | — | Apr 27 – May 25 | Jun 28 – Jul 12 |
| Beets | — | — | Apr 27 – May 25 | Jul 12 – Jul 26 |
| Potatoes | — | — | Apr 27 – May 18 | — |
| Swiss Chard | — | — | May 4 – Jun 1 | Jul 12 – Jul 26 |
| Cilantro | — | — | May 4 – May 25 | Jul 26 – Aug 16 |
| Green Beans | — | — | May 25 – Jun 15 | Jul 5 – Jul 19 |
| Sweet Corn | — | — | May 25 – Jun 8 | — |
| Sweet Potatoes | — | Jun 1 – Jun 22 | — | — |
| Garlic | — | — | — | Sep 6 – Oct 11 |
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 Wildrose 3nw, ND weather station, 34 km away (elevation 2,228 ft (679 m)).
Frost dates near Zahl
- Alamo May 18 · Sep 20
- Grenora May 16 · Sep 18
- Ambrose May 17 · Sep 23
- Fortuna May 19 · Sep 17
- Wildrose May 18 · Sep 20
- Epping May 21 · Sep 21
- Crosby May 17 · Sep 23
- Williston May 21 · Sep 21
- Ray May 11 · Sep 26
- Mcgregor May 18 · Sep 17
Frequently asked questions
When is the last frost in Zahl, ND?
The median last spring frost in Zahl, ND is May 18. There is still about a 10% chance of frost after May 30, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Zahl, ND?
The median first fall frost is September 20, with about a 10% chance of frost before September 7.
How long is the growing season in Zahl, ND?
About 125 days between the median last spring frost and first fall frost.
What planting zone is Zahl, ND?
Zahl, ND is in USDA hardiness zone 4a.