Frost dates for 57782Smithwick, SD
The average last spring frost in Smithwick is May 15 and the average first fall frost is September 30, giving a typical growing season of about 137 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 15
- Average first fall frost
- Sep 30
- Growing season
- 137 days
Safer after May 28 (1-in-10 risk)
Possible by Sep 16 (1-in-10 risk)
Last frost typically in 200 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 12 · May 25 · Jun 6 | Sep 9 · Sep 22 · Oct 4 | 119 days | 100% |
| Frost / freeze (32°F) | May 4 · May 15 · May 28 | Sep 16 · Sep 30 · Oct 13 | 137 days | 100% |
| Hard freeze (28°F) | Apr 22 · May 6 · May 18 | Sep 25 · Oct 9 · Oct 22 | 155 days | 100% |
Planting calendar for Smithwick
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 14 – Jun 20 |
| Tomatoes | Transplant outdoors | May 31 – Jun 10 |
| Peppers | Start seeds indoors | Apr 14 – May 15 |
| Peppers | Transplant outdoors | Jun 14 – Jul 15 |
| Eggplant | Start seeds indoors | May 1 – May 30 |
| Eggplant | Transplant outdoors | Jun 14 – Jul 15 |
| Cucumbers | Sow outdoors | Jun 14 – Jun 20 |
| Summer squash | Sow outdoors | May 31 – Jul 15 |
| Winter squash & pumpkins | Sow outdoors | Jun 14 – Jul 15 |
| Snap beans | Sow outdoors | May 31 – Jul 13 |
| Sweet corn | Sow outdoors | May 31 – Jun 10 |
| Watermelon & cantaloupe | Sow outdoors | Jun 14 – Jul 15 |
| Okra | Sow outdoors | Jun 7 – Jun 30 |
| Peas | Sow outdoors (spring) | Apr 14 – May 30 |
| Potatoes | Plant outdoors (spring) | Apr 14 – Jun 14 |
| Onions | Start seeds indoors (spring) | Mar 3 – Mar 30 |
| Onions | Transplant outdoors (spring) | May 1 – May 30 |
| Broccoli | Start seeds indoors (spring) | Mar 27 – Apr 30 |
| Broccoli | Transplant outdoors (spring) | May 1 – May 30 |
| Broccoli | Start seeds indoors (fall) | May 31 – Jun 10 |
| Broccoli | Transplant outdoors (fall) | Jun 30 – Jul 11 |
| Cabbage | Start seeds indoors (spring) | Mar 17 – Apr 14 |
| Cabbage | Transplant outdoors (spring) | Apr 14 – May 15 |
| Cabbage | Start seeds indoors (fall) | May 21 – Jun 20 |
| Cabbage | Transplant outdoors (fall) | Jun 20 – Jul 21 |
| Leaf lettuce | Sow outdoors (spring) | Apr 14 – Jun 30 |
| Leaf lettuce | Sow outdoors (fall) | Jun 20 – Aug 6 |
| Spinach | Sow outdoors (spring) | Apr 7 – May 21 |
| Spinach | Sow outdoors (fall) | Jul 7 – Aug 11 |
| Radishes | Sow outdoors (spring) | Apr 14 – Jun 4 |
| Radishes | Sow outdoors (fall) | Jun 20 – Aug 21 |
| Kale | Sow outdoors (spring) | May 1 – May 21 |
| Kale | Sow outdoors (fall) | Jun 13 – Jul 21 |
| Carrots | Sow outdoors (spring) | May 15 – Jun 30 |
| Carrots | Sow outdoors (fall) | May 21 – Jul 6 |
| Garlic | Plant outdoors (fall) | Sep 20 – Oct 21 |
Where these dates come from
ZIP code 57782 is matched to the NOAA station Oelrichs, SD, 12.7 km away, at 3,348 ft elevation (100 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Oelrichs, SD (used) | 3,348 ft | May 15 | Sep 30 |
| Oral, SD | 2,960 ft | May 15 | Sep 27 |
| Hot Springs, SD | 3,560 ft | May 16 | Sep 27 |
| Wind Cave, SD | 4,155 ft | May 15 | Sep 29 |
Frost dates near Smithwick
- Oral, SD 57766 · last May 15, first Sep 27
- Oelrichs, SD 57763 · last May 15, first Sep 30
- Buffalo Gap, SD 57722 · last May 15, first Sep 27
- Hot Springs, SD 57747 · last May 16, first Sep 27
- Fairburn, SD 57738 · last May 16, first Sep 27
- Oglala, SD 57764 · last May 7, first Oct 4
- Custer, SD 57730 · last May 15, first Sep 29
- Pringle, SD 57773 · last Jun 1, first Sep 10
Frequently asked questions
- When is the last frost in Smithwick, SD?
- For ZIP code 57782, the average last spring frost (32°F) is May 15, based on NOAA 1991-2020 climate normals for the Oelrichs, SD weather station. There is a 1-in-10 chance of a frost after May 28.
- When is the first frost in Smithwick, SD?
- The average first fall frost (32°F) is September 30. There is a 1-in-10 chance of frost by September 16, so tender plants are at risk from that point on.
- How long is the growing season in 57782?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 137 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.