When to plant in Jamestown, ND
USDA Zone 4bHere are the average frost dates, USDA hardiness zone, and a month-by-month planting calendar for Jamestown, North Dakota — all computed from Jamestown's nearest NOAA weather station.
In zone 4b, Jamestown winters are severe; choose cold-hardy perennials and time annuals carefully around the frost dates above.
The average first fall frost in Jamestown is now 5 days later than in the 1981–2010 normals. See how frost dates are shifting nationwide →
Frost probability
JAMESTOWN STATE HOSP · 1991–2020The date the last spring and first fall frost occur, by threshold and probability. A 90% date is later in spring — and earlier in fall — than a 10% date; the 50% · 32°F row is what most gardeners plan around. These are Jamestown’s own odds, recorded at JAMESTOWN STATE HOSP.
| Threshold | SPRING 10% | SPRING 50% | SPRING 90% | FALL 10% | FALL 50% | FALL 90% |
|---|---|---|---|---|---|---|
| 36°F | May 31 | May 17 | May 6 | Sep 10 | Sep 21 | Oct 1 |
| 32°F | May 21 | May 8 | Apr 26 | Sep 17 | Sep 29 | Oct 11 |
| 28°F | May 12 | Apr 30 | Apr 16 | Sep 26 | Oct 7 | Oct 21 |
Download this table as CSV ↓ — every threshold and probability, plus this city’s planting-window dates.
What to plant now
TODAY · JULY 19Full-year planting calendar
Each bar is the exact window to take a planting action in Jamestown, drawn to the day from the local frost dates. The dashed line is today.
Nearby weather stations
3 within 42 km · complete 32°F normalsWhen stations disagree by more than a few days, that spread is real microclimate variation — elevation, water, urban heat. Judge which station best matches your own yard.
Jamestown planting FAQ
When is the last spring frost in Jamestown, ND?
Plan for the last spring frost in Jamestown around May 8 (the date it has a 50% chance of a 32°F freeze). Anything frost-sensitive should go out after it.
When is the first fall frost in Jamestown, ND?
The first fall frost in Jamestown typically arrives around September 29 (50% probability at 32°F). Harvest or protect frost-sensitive crops before then.
What hardiness zone is Jamestown in?
Jamestown is in USDA hardiness zone 4b. In zone 4b, winters are cold — pick cold-hardy varieties and protect tender crops.
How long is the growing season in Jamestown?
Jamestown has about 144 frost-free days — a short growing season — between the average last spring frost (May 8) and first fall frost (September 29).
When should I plant tomatoes in Jamestown?
For Jamestown, sow tomatoes indoors about March 13–March 27 and move the seedlings out around May 15, after the last spring frost.
Never miss a window in Jamestown
An email when it’s time to start seeds, transplant, and sow — timed to Jamestown’s frost dates. Double opt-in, one-click unsubscribe, no spam.
Nearby cities
8 within reach- West Fargo · 136 km
- Fargo · 142 km
- Moorhead · 148 km
- Bismarck · 158 km
- Aberdeen · 161 km
- Grand Forks · 165 km
- Mandan · 167 km
- Fergus Falls · 212 km
Frost dates recorded at JAMESTOWN STATE HOSP, 2 km from the city center · 1991–2020 NOAA climate normals · zone from the USDA/PRISM 2023 map. How we compute this.
BlissGarden. "When to Plant in Jamestown, ND — Frost Dates & Zone 4b." Frost normals: NOAA NCEI U.S. Climate Normals 1991–2020, station USC00324418. Retrieved from https://blissgarden.com/north-dakota/jamestown.