Frost dates for 58844Fortuna, ND
The average last spring frost in Fortuna is May 19 and the average first fall frost is September 17, giving a typical growing season of about 121 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 19
- Average first fall frost
- Sep 17
- Growing season
- 121 days
Safer after May 31 (1-in-10 risk)
Possible by Sep 4 (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 18 · May 29 · Jun 14 | Aug 25 · Sep 8 · Sep 20 | 100 days | 100% |
| Frost / freeze (32°F) | May 8 · May 19 · May 31 | Sep 4 · Sep 17 · Sep 28 | 121 days | 100% |
| Hard freeze (28°F) | Apr 28 · May 10 · May 22 | Sep 13 · Sep 26 · Oct 8 | 138 days | 100% |
Planting calendar for Fortuna
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 18 – Jun 24 |
| Tomatoes | Transplant outdoors | Jun 4 – May 28 |
| Peppers | Start seeds indoors | Apr 18 – May 19 |
| Peppers | Transplant outdoors | Jun 18 – Jul 19 |
| Eggplant | Start seeds indoors | May 5 – Jun 3 |
| Eggplant | Transplant outdoors | Jun 18 – Jul 19 |
| Cucumbers | Sow outdoors | Jun 18 – Jun 7 |
| Summer squash | Sow outdoors | Jun 4 – Jul 19 |
| Winter squash & pumpkins | Sow outdoors | Jun 18 – Jul 19 |
| Snap beans | Sow outdoors | Jun 4 – Jun 30 |
| Sweet corn | Sow outdoors | Jun 4 – May 28 |
| Watermelon & cantaloupe | Sow outdoors | Jun 18 – Jul 19 |
| Okra | Sow outdoors | Jun 11 – Jul 4 |
| Peas | Sow outdoors (spring) | Apr 18 – Jun 3 |
| Potatoes | Plant outdoors (spring) | Apr 18 – Jun 18 |
| Onions | Start seeds indoors (spring) | Mar 7 – Apr 3 |
| Onions | Transplant outdoors (spring) | May 5 – Jun 3 |
| Broccoli | Start seeds indoors (spring) | Mar 31 – May 4 |
| Broccoli | Transplant outdoors (spring) | May 5 – Jun 3 |
| Broccoli | Start seeds indoors (fall) | May 18 – May 28 |
| Broccoli | Transplant outdoors (fall) | Jun 17 – Jun 28 |
| Cabbage | Start seeds indoors (spring) | Mar 21 – Apr 18 |
| Cabbage | Transplant outdoors (spring) | Apr 18 – May 19 |
| Cabbage | Start seeds indoors (fall) | May 8 – Jun 7 |
| Cabbage | Transplant outdoors (fall) | Jun 7 – Jul 8 |
| Leaf lettuce | Sow outdoors (spring) | Apr 18 – Jul 4 |
| Leaf lettuce | Sow outdoors (fall) | Jun 7 – Jul 24 |
| Spinach | Sow outdoors (spring) | Apr 11 – May 25 |
| Spinach | Sow outdoors (fall) | Jun 24 – Jul 29 |
| Radishes | Sow outdoors (spring) | Apr 18 – Jun 8 |
| Radishes | Sow outdoors (fall) | Jun 7 – Aug 8 |
| Kale | Sow outdoors (spring) | May 5 – May 25 |
| Kale | Sow outdoors (fall) | May 31 – Jul 8 |
| Carrots | Sow outdoors (spring) | May 19 – Jul 4 |
| Carrots | Sow outdoors (fall) | May 8 – Jun 23 |
| Garlic | Plant outdoors (fall) | Sep 7 – Oct 8 |
Where these dates come from
ZIP code 58844 is matched to the NOAA station Fortuna 1 W, ND, 5.6 km away, at 2,350 ft elevation (109 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Fortuna 1 W, ND (used) | 2,350 ft | May 19 | Sep 17 |
| Westby, MT | 2,103 ft | May 18 | Sep 21 |
| Crosby, ND | 1,959 ft | May 17 | Sep 23 |
| Wildrose 3Nw, ND | 2,227 ft | May 18 | Sep 20 |
Frost dates near Fortuna
- Ambrose, ND 58833 · last May 17, first Sep 23
- Westby, MT 59275 · last May 18, first Sep 21
- Zahl, ND 58856 · last May 18, first Sep 20
- Crosby, ND 58730 · last May 17, first Sep 23
- Alamo, ND 58830 · last May 18, first Sep 20
- Grenora, ND 58845 · last May 18, first Sep 21
- Dagmar, MT 59219 · last May 16, first Sep 18
- Noonan, ND 58765 · last May 17, first Sep 23
Frequently asked questions
- When is the last frost in Fortuna, ND?
- For ZIP code 58844, the average last spring frost (32°F) is May 19, based on NOAA 1991-2020 climate normals for the Fortuna 1 W, ND weather station. There is a 1-in-10 chance of a frost after May 31.
- When is the first frost in Fortuna, ND?
- The average first fall frost (32°F) is September 17. There is a 1-in-10 chance of frost by September 4, so tender plants are at risk from that point on.
- How long is the growing season in 58844?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 121 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.