Frost dates for 58620Amidon, ND
The average last spring frost in Amidon is May 12 and the average first fall frost is September 29, giving a typical growing season of about 136 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 12
- Average first fall frost
- Sep 29
- Growing season
- 136 days
Safer after May 28 (1-in-10 risk)
Possible by Sep 14 (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 11 · May 24 · Jun 7 | Sep 5 · Sep 19 · Oct 1 | 117 days | 100% |
| Frost / freeze (32°F) | May 2 · May 12 · May 28 | Sep 14 · Sep 29 · Oct 10 | 136 days | 100% |
| Hard freeze (28°F) | Apr 17 · May 3 · May 17 | Sep 23 · Oct 6 · Oct 20 | 154 days | 100% |
Planting calendar for Amidon
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 9 |
| 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 19 |
| Summer squash | Sow outdoors | May 28 – Jul 12 |
| Winter squash & pumpkins | Sow outdoors | Jun 11 – Jul 12 |
| Snap beans | Sow outdoors | May 28 – Jul 12 |
| Sweet corn | Sow outdoors | May 28 – Jun 9 |
| 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 30 – Jun 9 |
| Broccoli | Transplant outdoors (fall) | Jun 29 – Jul 10 |
| Cabbage | Start seeds indoors (spring) | Mar 14 – Apr 11 |
| Cabbage | Transplant outdoors (spring) | Apr 11 – May 12 |
| Cabbage | Start seeds indoors (fall) | May 20 – Jun 19 |
| Cabbage | Transplant outdoors (fall) | Jun 19 – Jul 20 |
| Leaf lettuce | Sow outdoors (spring) | Apr 11 – Jun 27 |
| Leaf lettuce | Sow outdoors (fall) | Jun 19 – Aug 5 |
| Spinach | Sow outdoors (spring) | Apr 4 – May 18 |
| Spinach | Sow outdoors (fall) | Jul 6 – Aug 10 |
| Radishes | Sow outdoors (spring) | Apr 11 – Jun 1 |
| Radishes | Sow outdoors (fall) | Jun 19 – Aug 20 |
| Kale | Sow outdoors (spring) | Apr 28 – May 18 |
| Kale | Sow outdoors (fall) | Jun 12 – Jul 20 |
| Carrots | Sow outdoors (spring) | May 12 – Jun 27 |
| Carrots | Sow outdoors (fall) | May 20 – Jul 5 |
| Garlic | Plant outdoors (fall) | Sep 19 – Oct 20 |
Where these dates come from
ZIP code 58620 is matched to the NOAA station Amidon, ND, 5.3 km away, at 2,910 ft elevation (62 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Amidon, ND (used) | 2,910 ft | May 12 | Sep 29 |
| Bowman, ND | 2,983 ft | May 16 | Sep 25 |
| New England, ND | 2,600 ft | May 16 | Sep 24 |
| Medora 7 E, ND | 2,771 ft | May 9 | Sep 30 |
Frost dates near Amidon
- Bowman, ND 58623 · last May 16, first Sep 25
- New England, ND 58647 · last May 16, first Sep 24
- Scranton, ND 58653 · last May 16, first Sep 25
- Belfield, ND 58622 · last May 9, first Sep 30
- South Heart, ND 58655 · last May 18, first Sep 25
- Reeder, ND 58649 · last May 24, first Sep 18
- Rhame, ND 58651 · last May 16, first Sep 25
- Marmarth, ND 58643 · last May 16, first Sep 26
Frequently asked questions
- When is the last frost in Amidon, ND?
- For ZIP code 58620, the average last spring frost (32°F) is May 12, based on NOAA 1991-2020 climate normals for the Amidon, ND weather station. There is a 1-in-10 chance of a frost after May 28.
- When is the first frost in Amidon, ND?
- The average first fall frost (32°F) is September 29. There is a 1-in-10 chance of frost by September 14, so tender plants are at risk from that point on.
- How long is the growing season in 58620?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 136 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.