Frost dates for 58363Perth, ND
The average last spring frost in Perth is May 20 and the average first fall frost is September 26, giving a typical growing season of about 128 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 20
- Average first fall frost
- Sep 26
- Growing season
- 128 days
Safer after May 31 (1-in-10 risk)
Possible by Sep 14 (1-in-10 risk)
Last frost typically in 205 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 10 | Sep 5 · Sep 18 · Sep 28 | 111 days | 100% |
| Frost / freeze (32°F) | May 8 · May 20 · May 31 | Sep 14 · Sep 26 · Oct 8 | 128 days | 100% |
| Hard freeze (28°F) | Apr 30 · May 11 · May 24 | Sep 21 · Oct 3 · Oct 18 | 146 days | 100% |
Planting calendar for Perth
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 19 – Jun 25 |
| Tomatoes | Transplant outdoors | Jun 5 – Jun 6 |
| Peppers | Start seeds indoors | Apr 19 – May 20 |
| Peppers | Transplant outdoors | Jun 19 – Jul 20 |
| Eggplant | Start seeds indoors | May 6 – Jun 4 |
| Eggplant | Transplant outdoors | Jun 19 – Jul 20 |
| Cucumbers | Sow outdoors | Jun 19 – Jun 16 |
| Summer squash | Sow outdoors | Jun 5 – Jul 20 |
| Winter squash & pumpkins | Sow outdoors | Jun 19 – Jul 20 |
| Snap beans | Sow outdoors | Jun 5 – Jul 9 |
| Sweet corn | Sow outdoors | Jun 5 – Jun 6 |
| Watermelon & cantaloupe | Sow outdoors | Jun 19 – Jul 20 |
| Okra | Sow outdoors | Jun 12 – Jul 5 |
| Peas | Sow outdoors (spring) | Apr 19 – Jun 4 |
| Potatoes | Plant outdoors (spring) | Apr 19 – Jun 19 |
| Onions | Start seeds indoors (spring) | Mar 8 – Apr 4 |
| Onions | Transplant outdoors (spring) | May 6 – Jun 4 |
| Broccoli | Start seeds indoors (spring) | Apr 1 – May 5 |
| Broccoli | Transplant outdoors (spring) | May 6 – Jun 4 |
| Broccoli | Start seeds indoors (fall) | May 27 – Jun 6 |
| Broccoli | Transplant outdoors (fall) | Jun 26 – Jul 7 |
| Cabbage | Start seeds indoors (spring) | Mar 22 – Apr 19 |
| Cabbage | Transplant outdoors (spring) | Apr 19 – May 20 |
| Cabbage | Start seeds indoors (fall) | May 17 – Jun 16 |
| Cabbage | Transplant outdoors (fall) | Jun 16 – Jul 17 |
| Leaf lettuce | Sow outdoors (spring) | Apr 19 – Jul 5 |
| Leaf lettuce | Sow outdoors (fall) | Jun 16 – Aug 2 |
| Spinach | Sow outdoors (spring) | Apr 12 – May 26 |
| Spinach | Sow outdoors (fall) | Jul 3 – Aug 7 |
| Radishes | Sow outdoors (spring) | Apr 19 – Jun 9 |
| Radishes | Sow outdoors (fall) | Jun 16 – Aug 17 |
| Kale | Sow outdoors (spring) | May 6 – May 26 |
| Kale | Sow outdoors (fall) | Jun 9 – Jul 17 |
| Carrots | Sow outdoors (spring) | May 20 – Jul 5 |
| Carrots | Sow outdoors (fall) | May 17 – Jul 2 |
| Garlic | Plant outdoors (fall) | Sep 16 – Oct 17 |
Where these dates come from
ZIP code 58363 is matched to the NOAA station Rolla 1Ne, ND, 17.7 km away, at 1,833 ft elevation (111 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Rolla 1Ne, ND (used) | 1,833 ft | May 20 | Sep 26 |
| Belcourt Keya Radio, ND | 1,960 ft | May 19 | Sep 24 |
| Hansboro 4 Nne, ND | 1,540 ft | May 18 | Sep 23 |
| Rolette 3Se, ND | 1,620 ft | May 22 | Sep 20 |
Frost dates near Perth
- Bisbee, ND 58317 · last May 22, first Sep 20
- Agate, ND 58310 · last May 22, first Sep 20
- Hansboro, ND 58339 · last May 20, first Sep 26
- Rolla, ND 58367 · last May 20, first Sep 26
- Mylo, ND 58353 · last May 22, first Sep 20
- Rocklake, ND 58365 · last May 18, first Sep 23
- Belcourt, ND 58316 · last May 19, first Sep 24
- Egeland, ND 58331 · last May 18, first Sep 23
Frequently asked questions
- When is the last frost in Perth, ND?
- For ZIP code 58363, the average last spring frost (32°F) is May 20, based on NOAA 1991-2020 climate normals for the Rolla 1Ne, ND weather station. There is a 1-in-10 chance of a frost after May 31.
- When is the first frost in Perth, ND?
- The average first fall frost (32°F) is September 26. 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 58363?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 128 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.