Frost dates for 57750Interior, SD
The average last spring frost in Interior is May 5 and the average first fall frost is October 7, giving a typical growing season of about 152 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 5
- Average first fall frost
- Oct 7
- Growing season
- 152 days
Safer after May 20 (1-in-10 risk)
Possible by Sep 23 (1-in-10 risk)
Last frost typically in 185 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 3 · May 15 · May 30 | Sep 14 · Sep 27 · Oct 10 | 132 days | 100% |
| Frost / freeze (32°F) | Apr 22 · May 5 · May 20 | Sep 23 · Oct 7 · Oct 20 | 152 days | 100% |
| Hard freeze (28°F) | Apr 10 · Apr 25 · May 7 | Oct 1 · Oct 15 · Oct 27 | 173 days | 100% |
Planting calendar for Interior
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 4 – Jun 10 |
| Tomatoes | Transplant outdoors | May 21 – Jun 17 |
| Peppers | Start seeds indoors | Apr 4 – May 5 |
| Peppers | Transplant outdoors | Jun 4 – Jul 5 |
| Eggplant | Start seeds indoors | Apr 21 – May 20 |
| Eggplant | Transplant outdoors | Jun 4 – Jul 5 |
| Cucumbers | Sow outdoors | Jun 4 – Jun 27 |
| Summer squash | Sow outdoors | May 21 – Jul 5 |
| Winter squash & pumpkins | Sow outdoors | Jun 4 – Jul 5 |
| Snap beans | Sow outdoors | May 21 – Jul 20 |
| Sweet corn | Sow outdoors | May 21 – Jun 17 |
| Watermelon & cantaloupe | Sow outdoors | Jun 4 – Jul 5 |
| Okra | Sow outdoors | May 28 – Jun 20 |
| Peas | Sow outdoors (spring) | Apr 4 – May 20 |
| Potatoes | Plant outdoors (spring) | Apr 4 – Jun 4 |
| Onions | Start seeds indoors (spring) | Feb 21 – Mar 20 |
| Onions | Transplant outdoors (spring) | Apr 21 – May 20 |
| Broccoli | Start seeds indoors (spring) | Mar 17 – Apr 20 |
| Broccoli | Transplant outdoors (spring) | Apr 21 – May 20 |
| Broccoli | Start seeds indoors (fall) | Jun 7 – Jun 17 |
| Broccoli | Transplant outdoors (fall) | Jul 7 – Jul 18 |
| Cabbage | Start seeds indoors (spring) | Mar 7 – Apr 4 |
| Cabbage | Transplant outdoors (spring) | Apr 4 – May 5 |
| Cabbage | Start seeds indoors (fall) | May 28 – Jun 27 |
| Cabbage | Transplant outdoors (fall) | Jun 27 – Jul 28 |
| Leaf lettuce | Sow outdoors (spring) | Apr 4 – Jun 20 |
| Leaf lettuce | Sow outdoors (fall) | Jun 27 – Aug 13 |
| Spinach | Sow outdoors (spring) | Mar 28 – May 11 |
| Spinach | Sow outdoors (fall) | Jul 14 – Aug 18 |
| Radishes | Sow outdoors (spring) | Apr 4 – May 25 |
| Radishes | Sow outdoors (fall) | Jun 27 – Aug 28 |
| Kale | Sow outdoors (spring) | Apr 21 – May 11 |
| Kale | Sow outdoors (fall) | Jun 20 – Jul 28 |
| Carrots | Sow outdoors (spring) | May 5 – Jun 20 |
| Carrots | Sow outdoors (fall) | May 28 – Jul 13 |
| Garlic | Plant outdoors (fall) | Sep 27 – Oct 28 |
Where these dates come from
ZIP code 57750 is matched to the NOAA station Interior 3 Ne, SD, 2.6 km away, at 2,440 ft elevation (78 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Interior 3 Ne, SD (used) | 2,440 ft | May 5 | Oct 7 |
| Cottonwood 2 E, SD | 2,373 ft | May 16 | Sep 26 |
| Kyle 2 E, SD | 2,958 ft | May 11 | Oct 1 |
| Philip Ap, SD | 2,206 ft | May 11 | Sep 30 |
Frost dates near Interior
- Wanblee, SD 57577 · last May 9, first Oct 1
- Wall, SD 57790 · last May 10, first Oct 1
- Kadoka, SD 57543 · last May 16, first Sep 26
- Kyle, SD 57752 · last May 11, first Oct 1
- Quinn, SD 57775 · last May 16, first Sep 26
- Philip, SD 57567 · last May 11, first Sep 30
- Scenic, SD 57780 · last May 17, first Sep 25
- Allen, SD 57714 · last May 13, first Oct 2
Frequently asked questions
- When is the last frost in Interior, SD?
- For ZIP code 57750, the average last spring frost (32°F) is May 5, based on NOAA 1991-2020 climate normals for the Interior 3 Ne, SD weather station. There is a 1-in-10 chance of a frost after May 20.
- When is the first frost in Interior, SD?
- The average first fall frost (32°F) is October 7. There is a 1-in-10 chance of frost by September 23, so tender plants are at risk from that point on.
- How long is the growing season in 57750?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 152 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.