Trenton, ND frost dates
Last spring frostMay 13median date
First fall frostSep 26median date
Growing season136 daysfrost-free
Hardiness zone4aZone 4a
How Trenton compares
- In 8 years out of 10, the last spring frost in Trenton falls between May 1 and May 25, a 24-day window. The first fall frost falls between September 14 and October 8.
- The median last frost is 1 day later than the North Dakota median of May 12.
- Its 136-day growing season is longer than 37% 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 177 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 1 |
| 50% (median) | May 13 |
| 10% (safe for tender plants) | May 25 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 14 |
| 50% (median) | September 26 |
| 90% (late) | October 8 |
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 Trenton, ND
Trenton, ND frost dates — last frost May 13, first frost Sep 26, zone 4a. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Feb 18 to Mar 4Transplant outside: Apr 15 to Apr 29
Start indoors: Mar 4 to Mar 18Transplant outside: May 27 to Jun 10
Start indoors: Mar 4 to Mar 18Transplant outside: May 27 to Jun 10
Start indoors: Mar 18 to Apr 1Transplant outside: May 20 to Jun 3
Start indoors: Mar 18 to Apr 1Transplant outside: Apr 22 to May 6Sow outdoors: Apr 15 to May 20Plant for fall: Aug 1 to Aug 29
Start indoors: Mar 18 to Apr 1Transplant outside: Apr 15 to Apr 29Sow outdoors: Apr 15 to Apr 29Plant for fall: Jul 18 to Aug 8
Start indoors: Mar 18 to Apr 1Transplant outside: Apr 29 to May 13Plant for fall: Jun 20 to Jul 11
Start indoors: Mar 18 to Apr 1Transplant outside: Apr 22 to May 6Plant for fall: Jun 20 to Jul 11
Start indoors: Mar 18 to Apr 1Transplant outside: Apr 29 to May 13Plant for fall: Jun 20 to Jul 11
Start indoors: Apr 1 to Apr 15Transplant outside: Jun 3 to Jun 17Sow outdoors: Jun 3 to Jun 17
Start indoors: Apr 1 to Apr 15Transplant outside: May 20 to Jun 3
Sow outdoors: Apr 1 to Apr 22Plant for fall: Jul 4 to Jul 25
Sow outdoors: Apr 1 to Apr 22Plant for fall: Aug 1 to Aug 22
Sow outdoors: Apr 8 to May 20Plant for fall: Aug 15 to Sep 5
Start indoors: Apr 15 to Apr 22Transplant outside: May 27 to Jun 3Sow outdoors: May 20 to Jun 3Plant for fall: Jul 11 to Jul 25
Start indoors: Apr 15 to Apr 22Sow outdoors: May 20 to Jun 3Plant for fall: Jul 18 to Aug 1
Start indoors: Apr 15 to Apr 22Sow outdoors: May 20 to Jun 3
Start indoors: Apr 15 to Apr 22Transplant outside: May 27 to Jun 10
Sow outdoors: Apr 22 to May 20Plant for fall: Jul 4 to Jul 18
Sow outdoors: Apr 22 to May 20Plant for fall: Jul 18 to Aug 1
Sow outdoors: Apr 22 to May 13
Sow outdoors: Apr 29 to May 27Plant for fall: Jul 18 to Aug 1
Sow outdoors: Apr 29 to May 20Plant for fall: Aug 1 to Aug 22
Sow outdoors: May 20 to Jun 10Plant for fall: Jul 11 to Jul 25
Sow outdoors: May 20 to Jun 3
Transplant outside: May 27 to Jun 17
Plant for fall: Sep 12 to Oct 17
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Trenton, ND
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 18 – Mar 4 | Apr 15 – Apr 29 | — | — |
| Peppers | Mar 4 – Mar 18 | May 27 – Jun 10 | — | — |
| Eggplant | Mar 4 – Mar 18 | May 27 – Jun 10 | — | — |
| Tomatoes | Mar 18 – Apr 1 | May 20 – Jun 3 | — | — |
| Lettuce | Mar 18 – Apr 1 | Apr 22 – May 6 | Apr 15 – May 20 | Aug 1 – Aug 29 |
| Kale | Mar 18 – Apr 1 | Apr 15 – Apr 29 | Apr 15 – Apr 29 | Jul 18 – Aug 8 |
| Broccoli | Mar 18 – Apr 1 | Apr 29 – May 13 | — | Jun 20 – Jul 11 |
| Cabbage | Mar 18 – Apr 1 | Apr 22 – May 6 | — | Jun 20 – Jul 11 |
| Cauliflower | Mar 18 – Apr 1 | Apr 29 – May 13 | — | Jun 20 – Jul 11 |
| Okra | Apr 1 – Apr 15 | Jun 3 – Jun 17 | Jun 3 – Jun 17 | — |
| Basil | Apr 1 – Apr 15 | May 20 – Jun 3 | — | — |
| Peas | — | — | Apr 1 – Apr 22 | Jul 4 – Jul 25 |
| Spinach | — | — | Apr 1 – Apr 22 | Aug 1 – Aug 22 |
| Radishes | — | — | Apr 8 – May 20 | Aug 15 – Sep 5 |
| Cucumbers | Apr 15 – Apr 22 | May 27 – Jun 3 | May 20 – Jun 3 | Jul 11 – Jul 25 |
| Zucchini & Summer Squash | Apr 15 – Apr 22 | — | May 20 – Jun 3 | Jul 18 – Aug 1 |
| Winter Squash & Pumpkins | Apr 15 – Apr 22 | — | May 20 – Jun 3 | — |
| Melons & Watermelon | Apr 15 – Apr 22 | May 27 – Jun 10 | — | — |
| Carrots | — | — | Apr 22 – May 20 | Jul 4 – Jul 18 |
| Beets | — | — | Apr 22 – May 20 | Jul 18 – Aug 1 |
| Potatoes | — | — | Apr 22 – May 13 | — |
| Swiss Chard | — | — | Apr 29 – May 27 | Jul 18 – Aug 1 |
| Cilantro | — | — | Apr 29 – May 20 | Aug 1 – Aug 22 |
| Green Beans | — | — | May 20 – Jun 10 | Jul 11 – Jul 25 |
| Sweet Corn | — | — | May 20 – Jun 3 | — |
| Sweet Potatoes | — | May 27 – Jun 17 | — | — |
| Garlic | — | — | — | Sep 12 – Oct 17 |
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 Williston Exp Farm, ND weather station, 10 km away (elevation 2,106 ft (642 m)).
Frost dates near Trenton
- Williston May 21 · Sep 21
- Cartwright May 11 · Sep 27
- Alexander May 9 · Sep 27
- Arnegard May 9 · Sep 27
- Epping May 21 · Sep 21
- Grenora May 16 · Sep 18
- Watford City May 9 · Sep 27
- Ray May 11 · Sep 26
- Zahl May 18 · Sep 20
- Alamo May 18 · Sep 20
Frequently asked questions
When is the last frost in Trenton, ND?
The median last spring frost in Trenton, ND is May 13. 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 Trenton, ND?
The median first fall frost is September 26, with about a 10% chance of frost before September 14.
How long is the growing season in Trenton, ND?
About 136 days between the median last spring frost and first fall frost.
What planting zone is Trenton, ND?
Trenton, ND is in USDA hardiness zone 4a.