Frost dates for 58577Washburn, ND
The average last spring frost in Washburn is May 12 and the average first fall frost is September 30, giving a typical growing season of about 140 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 12
- Average first fall frost
- Sep 30
- Growing season
- 140 days
Safer after May 25 (1-in-10 risk)
Possible by Sep 18 (1-in-10 risk)
Last frost typically in 190 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 9 · May 22 · Jun 2 | Sep 9 · Sep 22 · Oct 2 | 122 days | 100% |
| Frost / freeze (32°F) | Apr 30 · May 12 · May 25 | Sep 18 · Sep 30 · Oct 11 | 140 days | 100% |
| Hard freeze (28°F) | Apr 17 · May 3 · May 16 | Sep 27 · Oct 8 · Oct 20 | 159 days | 100% |
Planting calendar for Washburn
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 11 – Jun 17 |
| Tomatoes | Transplant outdoors | May 28 – Jun 10 |
| Peppers | Start seeds indoors | Apr 11 – May 12 |
| Peppers | Transplant outdoors | Jun 11 – Jul 12 |
| Eggplant | Start seeds indoors | Apr 28 – May 27 |
| Eggplant | Transplant outdoors | Jun 11 – Jul 12 |
| Cucumbers | Sow outdoors | Jun 11 – Jun 20 |
| Summer squash | Sow outdoors | May 28 – Jul 12 |
| Winter squash & pumpkins | Sow outdoors | Jun 11 – Jul 12 |
| Snap beans | Sow outdoors | May 28 – Jul 13 |
| Sweet corn | Sow outdoors | May 28 – Jun 10 |
| Watermelon & cantaloupe | Sow outdoors | Jun 11 – Jul 12 |
| Okra | Sow outdoors | Jun 4 – Jun 27 |
| Peas | Sow outdoors (spring) | Apr 11 – May 27 |
| Potatoes | Plant outdoors (spring) | Apr 11 – Jun 11 |
| Onions | Start seeds indoors (spring) | Feb 28 – Mar 27 |
| Onions | Transplant outdoors (spring) | Apr 28 – May 27 |
| Broccoli | Start seeds indoors (spring) | Mar 24 – Apr 27 |
| Broccoli | Transplant outdoors (spring) | Apr 28 – May 27 |
| Broccoli | Start seeds indoors (fall) | May 31 – Jun 10 |
| Broccoli | Transplant outdoors (fall) | Jun 30 – Jul 11 |
| Cabbage | Start seeds indoors (spring) | Mar 14 – Apr 11 |
| Cabbage | Transplant outdoors (spring) | Apr 11 – May 12 |
| Cabbage | Start seeds indoors (fall) | May 21 – Jun 20 |
| Cabbage | Transplant outdoors (fall) | Jun 20 – Jul 21 |
| Leaf lettuce | Sow outdoors (spring) | Apr 11 – Jun 27 |
| Leaf lettuce | Sow outdoors (fall) | Jun 20 – Aug 6 |
| Spinach | Sow outdoors (spring) | Apr 4 – May 18 |
| Spinach | Sow outdoors (fall) | Jul 7 – Aug 11 |
| Radishes | Sow outdoors (spring) | Apr 11 – Jun 1 |
| Radishes | Sow outdoors (fall) | Jun 20 – Aug 21 |
| Kale | Sow outdoors (spring) | Apr 28 – May 18 |
| Kale | Sow outdoors (fall) | Jun 13 – Jul 21 |
| Carrots | Sow outdoors (spring) | May 12 – Jun 27 |
| Carrots | Sow outdoors (fall) | May 21 – Jul 6 |
| Garlic | Plant outdoors (fall) | Sep 20 – Oct 21 |
Where these dates come from
ZIP code 58577 is matched to the NOAA station Washburn, ND, 2 km away, at 1,755 ft elevation (178 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Washburn, ND (used) | 1,755 ft | May 12 | Sep 30 |
| Underwood, ND | 2,045 ft | May 10 | Sep 29 |
| Wilton, ND | 2,188 ft | May 11 | Sep 30 |
| Turtle Lake, ND | 1,893 ft | May 14 | Sep 26 |
Frost dates near Washburn
- Underwood, ND 58576 · last May 10, first Sep 29
- Center, ND 58530 · last May 11, first Sep 29
- Wilton, ND 58579 · last May 11, first Sep 30
- Turtle Lake, ND 58575 · last May 14, first Sep 26
- Stanton, ND 58571 · last May 12, first Sep 30
- Mercer, ND 58559 · last May 14, first Sep 26
- Coleharbor, ND 58531 · last May 10, first Sep 29
- Riverdale, ND 58565 · last May 12, first Oct 3
Frequently asked questions
- When is the last frost in Washburn, ND?
- For ZIP code 58577, the average last spring frost (32°F) is May 12, based on NOAA 1991-2020 climate normals for the Washburn, ND weather station. There is a 1-in-10 chance of a frost after May 25.
- When is the first frost in Washburn, ND?
- The average first fall frost (32°F) is September 30. There is a 1-in-10 chance of frost by September 18, so tender plants are at risk from that point on.
- How long is the growing season in 58577?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 140 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.