Riverdale, ND frost dates
Last spring frostMay 12median date
First fall frostOct 3median date
Growing season144 daysfrost-free
Hardiness zone4aZone 4a
How Riverdale compares
- In 8 years out of 10, the last spring frost in Riverdale falls between April 30 and May 27, a 27-day window. The first fall frost falls between September 20 and October 14.
- The median last frost is the same as the North Dakota median of May 12.
- Its 144-day growing season is longer than 76% 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 178 nights a year at or below 32°F.
- Compared with Bismarck, ND, 89 km away, the last frost here is 2 days later than there and the growing season is 1 day longer.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 30 |
| 50% (median) | May 12 |
| 10% (safe for tender plants) | May 27 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 20 |
| 50% (median) | October 3 |
| 90% (late) | October 14 |
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 Riverdale, ND
Riverdale, ND frost dates — last frost May 12, first frost Oct 3, zone 4a. whenisthelastfrost.com
Crop
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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 8 to Sep 5
Start indoors: Mar 17 to Mar 31Transplant outside: Apr 14 to Apr 28Sow outdoors: Apr 14 to Apr 28Plant for fall: Jul 25 to Aug 15
Start indoors: Mar 17 to Mar 31Transplant outside: Apr 28 to May 12Plant for fall: Jun 27 to Jul 18
Start indoors: Mar 17 to Mar 31Transplant outside: Apr 21 to May 5Plant for fall: Jun 27 to Jul 18
Start indoors: Mar 17 to Mar 31Transplant outside: Apr 28 to May 12Plant for fall: Jun 27 to Jul 18
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 11 to Aug 1
Sow outdoors: Mar 31 to Apr 21Plant for fall: Aug 8 to Aug 29
Sow outdoors: Apr 7 to May 19Plant for fall: Aug 22 to Sep 12
Start indoors: Apr 14 to Apr 21Transplant outside: May 26 to Jun 2Sow outdoors: May 19 to Jun 2Plant for fall: Jul 18 to Aug 1
Start indoors: Apr 14 to Apr 21Sow outdoors: May 19 to Jun 2Plant for fall: Jul 25 to Aug 8
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 11 to Jul 25
Sow outdoors: Apr 21 to May 19Plant for fall: Jul 25 to Aug 8
Sow outdoors: Apr 21 to May 12
Sow outdoors: Apr 28 to May 26Plant for fall: Jul 25 to Aug 8
Sow outdoors: Apr 28 to May 19Plant for fall: Aug 8 to Aug 29
Sow outdoors: May 19 to Jun 9Plant for fall: Jul 18 to Aug 1
Sow outdoors: May 19 to Jun 2
Transplant outside: May 26 to Jun 16
Plant for fall: Sep 19 to Oct 24
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Riverdale, 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 8 – Sep 5 |
| Kale | Mar 17 – Mar 31 | Apr 14 – Apr 28 | Apr 14 – Apr 28 | Jul 25 – Aug 15 |
| Broccoli | Mar 17 – Mar 31 | Apr 28 – May 12 | — | Jun 27 – Jul 18 |
| Cabbage | Mar 17 – Mar 31 | Apr 21 – May 5 | — | Jun 27 – Jul 18 |
| Cauliflower | Mar 17 – Mar 31 | Apr 28 – May 12 | — | Jun 27 – Jul 18 |
| 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 11 – Aug 1 |
| Spinach | — | — | Mar 31 – Apr 21 | Aug 8 – Aug 29 |
| Radishes | — | — | Apr 7 – May 19 | Aug 22 – Sep 12 |
| Cucumbers | Apr 14 – Apr 21 | May 26 – Jun 2 | May 19 – Jun 2 | Jul 18 – Aug 1 |
| Zucchini & Summer Squash | Apr 14 – Apr 21 | — | May 19 – Jun 2 | Jul 25 – Aug 8 |
| 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 11 – Jul 25 |
| Beets | — | — | Apr 21 – May 19 | Jul 25 – Aug 8 |
| Potatoes | — | — | Apr 21 – May 12 | — |
| Swiss Chard | — | — | Apr 28 – May 26 | Jul 25 – Aug 8 |
| Cilantro | — | — | Apr 28 – May 19 | Aug 8 – Aug 29 |
| Green Beans | — | — | May 19 – Jun 9 | Jul 18 – Aug 1 |
| Sweet Corn | — | — | May 19 – Jun 2 | — |
| Sweet Potatoes | — | May 26 – Jun 16 | — | — |
| Garlic | — | — | — | Sep 19 – Oct 24 |
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 Riverdale, ND weather station, about 1 km away (elevation 1,962 ft (598 m)).
Frost dates near Riverdale
- Coleharbor May 10 · Sep 29
- Underwood May 10 · Sep 29
- Stanton May 12 · Oct 3
- Garrison May 14 · Sep 26
- Hazen May 21 · Sep 20
- Washburn May 12 · Sep 30
- Max May 10 · Sep 28
- Turtle Lake May 14 · Sep 26
- Benedict May 10 · Sep 28
- Roseglen May 14 · Sep 26
Frequently asked questions
When is the last frost in Riverdale, ND?
The median last spring frost in Riverdale, ND is May 12. There is still about a 10% chance of frost after May 27, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Riverdale, ND?
The median first fall frost is October 3, with about a 10% chance of frost before September 20.
How long is the growing season in Riverdale, ND?
About 144 days between the median last spring frost and first fall frost.
What planting zone is Riverdale, ND?
Riverdale, ND is in USDA hardiness zone 4a.