North Dakota Planting Zones by City and ZIP Code
North Dakota runs from zones 3b to 4b; 78% of its ZIPs are 4a, Fargo is 4a and Bismarck is 4a.
North Dakota runs from zones 3b to 4b
The coldest night of the winter averages -35°F to -30°F in the coldest of North Dakota’s ZIP codes and -25°F to -20°F in the warmest. Most of the state is zone 4a.
Planting zones of North Dakota cities
| City | Zone | Coldest night, on average | Since 2012 |
|---|---|---|---|
| Fargo58102 | 4a | -30°F to -25°F | same as 2012 |
| Bismarck58501 | 4a | -30°F to -25°F | same as 2012 |
| Grand Forks58201 | 4a | -30°F to -25°F | same as 2012 |
| Minot58701 | 4a | -30°F to -25°F | same as 2012 |
| Williston58801 | 4a | -30°F to -25°F | same as 2012 |
| Dickinson58601 | 4b | -25°F to -20°F | half a zone warmer than 2012 (4a) |
Tap a ZIP for that address’s frost dates and this month’s jobs.
Find your zone anywhere in North Dakota
A ZIP code or a town gives you its zone, how it moved since 2012, the frost dates at the nearest NOAA station, and the jobs for this month timed from them.
What to plant in North Dakota this month
The calendar for North Dakota's main zone, from vegetables to pruning and winter protection, each job tied to the extension page it comes from. Pick a month, or read the whole year below it.
Timed from the median frost dates of the 72 NOAA stations in North Dakota’s zone 4a: last spring frost May 12, first fall frost Sep 28. Your own ZIP’s frost dates move every window, so the ZIP tool times them for you.
Pick a month above to see every job in it.
The year at a glance
- Start vegetable seeds indoorsFeb to May
- Sow vegetables in the gardenApr to May
- Sow the fall vegetable gardenJun to Aug
- Set out transplantsApr to Jun
- Plant trees and shrubsMar 31 to May 26 and Sep 14 to Nov 2
- Plant garlicSep 14 to Oct 19
- Plant tulips and other spring bulbsOct 5 to Oct 12
- Divide fall-blooming perennialsApr 21 to Jun 2
- Divide spring and summer-blooming perennialsAug 17 to Sep 28
- Prune trees and summer-flowering shrubs while dormantMar 3 to Apr 14
- Prune spring-flowering shrubs after they bloomApr 28 to Jun 23
- Water evergreens and new plantings until the ground freezesAug 31 to Nov 9
- Mulch perennial crowns once the ground freezesNov 9 to Nov 23
- Pull back the winter mulchMar 24 to Apr 7
- Put hardware cloth around young tree trunksSep 28 to Nov 9
- Dig and store canna, dahlia and gladiolusSep 28 to Oct 5
- Cut back perennials after a hard freezeOct 5 to Nov 2
What changed in North Dakota since 2012
Every ZIP on both mapsCompared ZIP by ZIP from the 2023 and 2012 USDA tables; 405 North Dakota ZIP codes appear in both.
Why North Dakota’s zones moved
Of the cities above, Dickinson went from 4a to 4b.
The USDA explains the national picture: “When compared to the 2012 map, the 2023 version reveals that about half of the country shifted to the next warmer half zone, and the other half of the country remained in the same half zone.” The new map uses 1991 to 2020 and more than 13,000 weather stations, so it draws North Dakota’s hills, valleys and cities more finely than the 2012 map did.
A warmer zone changes which perennials and shrubs come through the winter, not when the garden gets planted; that still follows the frost dates.

Frost dates and seed starting in North Dakota
North Dakota planting zone questions
Planting zones by state
Sources. USDA Plant Hardiness Zone Map, ZIP code tables (2023 and 2012), PRISM Climate Group, Oregon State University; USDA Plant Hardiness Zone Map; USDA Unveils Updated Plant Hardiness Zone Map (USDA Agricultural Research Service, November 15, 2023); NOAA NCEI U.S. Climate Normals 1991-2020, annual/seasonal, by station (v1.0.1); NC State Extension Gardener Plant Toolbox. Zones are read from the PRISM ZIP code tables, read Oct 9, 2026; a ZIP code’s zone is the zone at its center. The calendar’s extension sources are listed on the planting zones page and under each job.