Frost dates for 58405Jamestown, ND
The average last spring frost in Jamestown is May 11 and the average first fall frost is September 28, giving a typical growing season of about 138 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 11
- Average first fall frost
- Sep 28
- Growing season
- 138 days
Safer after May 24 (1-in-10 risk)
Possible by Sep 15 (1-in-10 risk)
Last frost typically in 197 days
Frost risk by date
NOAA reports frost dates as probabilities. The middle date is the average (a 50% chance). For spring, the 10% date is a safer planting date: frost after it happens in about 1 year in 10. Light frost (36°F) can damage tender plants; a hard freeze (28°F) kills most annuals.
| Temperature | Last spring: 90% / 50% / 10% chance | First fall: 10% / 50% / 90% chance | Growing season (50%) | Years with at least one |
|---|---|---|---|---|
| Light frost (36°F) | May 8 · May 20 · Jun 2 | Sep 7 · Sep 19 · Sep 30 | 119 days | 100% |
| Frost / freeze (32°F) | Apr 28 · May 11 · May 24 | Sep 15 · Sep 28 · Oct 9 | 138 days | 100% |
| Hard freeze (28°F) | Apr 18 · May 1 · May 14 | Sep 25 · Oct 6 · Oct 20 | 157 days | 100% |
Planting calendar for Jamestown
Planting windows from the University of Maryland Extension calendar, shifted to your average frost dates. Use them as a starting point and adjust for seed packet instructions and local conditions.
| Crop | Task | Window |
|---|---|---|
| Tomatoes | Start seeds indoors | Apr 10 – Jun 16 |
| Tomatoes | Transplant outdoors | May 27 – Jun 8 |
| Peppers | Start seeds indoors | Apr 10 – May 11 |
| Peppers | Transplant outdoors | Jun 10 – Jul 11 |
| Eggplant | Start seeds indoors | Apr 27 – May 26 |
| Eggplant | Transplant outdoors | Jun 10 – Jul 11 |
| Cucumbers | Sow outdoors | Jun 10 – Jun 18 |
| Summer squash | Sow outdoors | May 27 – Jul 11 |
| Winter squash & pumpkins | Sow outdoors | Jun 10 – Jul 11 |
| Snap beans | Sow outdoors | May 27 – Jul 11 |
| Sweet corn | Sow outdoors | May 27 – Jun 8 |
| Watermelon & cantaloupe | Sow outdoors | Jun 10 – Jul 11 |
| Okra | Sow outdoors | Jun 3 – Jun 26 |
| Peas | Sow outdoors (spring) | Apr 10 – May 26 |
| Potatoes | Plant outdoors (spring) | Apr 10 – Jun 10 |
| Onions | Start seeds indoors (spring) | Feb 27 – Mar 26 |
| Onions | Transplant outdoors (spring) | Apr 27 – May 26 |
| Broccoli | Start seeds indoors (spring) | Mar 23 – Apr 26 |
| Broccoli | Transplant outdoors (spring) | Apr 27 – May 26 |
| Broccoli | Start seeds indoors (fall) | May 29 – Jun 8 |
| Broccoli | Transplant outdoors (fall) | Jun 28 – Jul 9 |
| Cabbage | Start seeds indoors (spring) | Mar 13 – Apr 10 |
| Cabbage | Transplant outdoors (spring) | Apr 10 – May 11 |
| Cabbage | Start seeds indoors (fall) | May 19 – Jun 18 |
| Cabbage | Transplant outdoors (fall) | Jun 18 – Jul 19 |
| Leaf lettuce | Sow outdoors (spring) | Apr 10 – Jun 26 |
| Leaf lettuce | Sow outdoors (fall) | Jun 18 – Aug 4 |
| Spinach | Sow outdoors (spring) | Apr 3 – May 17 |
| Spinach | Sow outdoors (fall) | Jul 5 – Aug 9 |
| Radishes | Sow outdoors (spring) | Apr 10 – May 31 |
| Radishes | Sow outdoors (fall) | Jun 18 – Aug 19 |
| Kale | Sow outdoors (spring) | Apr 27 – May 17 |
| Kale | Sow outdoors (fall) | Jun 11 – Jul 19 |
| Carrots | Sow outdoors (spring) | May 11 – Jun 26 |
| Carrots | Sow outdoors (fall) | May 19 – Jul 4 |
| Garlic | Plant outdoors (fall) | Sep 18 – Oct 19 |
Where these dates come from
ZIP code 58405 is matched to the NOAA station Jamestown Muni Ap, ND, 2.7 km away, at 1,494 ft elevation (14 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Jamestown Muni Ap, ND (used) | 1,494 ft | May 11 | Sep 28 |
| Jamestown State Hosp, ND | 1,467 ft | May 8 | Sep 29 |
| Edmunds Arrowwood Ref, ND | 1,460 ft | May 11 | Sep 28 |
| Gackle, ND | 1,951 ft | May 6 | Oct 4 |
Frost dates near Jamestown
- Jamestown, ND 58401 · last May 11, first Sep 28
- Spiritwood, ND 58481 · last May 11, first Sep 28
- Buchanan, ND 58420 · last May 11, first Sep 28
- Ypsilanti, ND 58497 · last May 8, first Sep 29
- Montpelier, ND 58472 · last May 8, first Sep 29
- Wimbledon, ND 58492 · last May 11, first Sep 28
- Cleveland, ND 58424 · last May 13, first Sep 30
- Sanborn, ND 58480 · last May 13, first Sep 26
Frequently asked questions
- When is the last frost in Jamestown, ND?
- For ZIP code 58405, the average last spring frost (32°F) is May 11, based on NOAA 1991-2020 climate normals for the Jamestown Muni Ap, ND weather station. There is a 1-in-10 chance of a frost after May 24.
- When is the first frost in Jamestown, ND?
- The average first fall frost (32°F) is September 28. There is a 1-in-10 chance of frost by September 15, so tender plants are at risk from that point on.
- How long is the growing season in 58405?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 138 days long.
- Are these frost dates a forecast?
- No. They are 30-year averages and probabilities from NOAA weather station records. Use them to plan, then watch your local forecast before planting tender crops or leaving them uncovered.