Frost dates for 57066Tyndall, SD
The average last spring frost in Tyndall is May 1 and the average first fall frost is October 7, giving a typical growing season of about 158 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 1
- Average first fall frost
- Oct 7
- Growing season
- 158 days
Safer after May 14 (1-in-10 risk)
Possible by Sep 24 (1-in-10 risk)
Last frost typically in 181 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) | Apr 29 · May 10 · May 22 | Sep 17 · Sep 30 · Oct 12 | 140 days | 100% |
| Frost / freeze (32°F) | Apr 18 · May 1 · May 14 | Sep 24 · Oct 7 · Oct 20 | 158 days | 100% |
| Hard freeze (28°F) | Apr 7 · Apr 21 · May 4 | Oct 1 · Oct 17 · Oct 29 | 177 days | 100% |
Planting calendar for Tyndall
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 | Mar 31 – Jun 6 |
| Tomatoes | Transplant outdoors | May 17 – Jun 17 |
| Peppers | Start seeds indoors | Mar 31 – May 1 |
| Peppers | Transplant outdoors | May 31 – Jul 1 |
| Eggplant | Start seeds indoors | Apr 17 – May 16 |
| Eggplant | Transplant outdoors | May 31 – Jul 1 |
| Cucumbers | Sow outdoors | May 31 – Jun 27 |
| Summer squash | Sow outdoors | May 17 – Jul 1 |
| Winter squash & pumpkins | Sow outdoors | May 31 – Jul 1 |
| Snap beans | Sow outdoors | May 17 – Jul 20 |
| Sweet corn | Sow outdoors | May 17 – Jun 17 |
| Watermelon & cantaloupe | Sow outdoors | May 31 – Jul 1 |
| Okra | Sow outdoors | May 24 – Jun 16 |
| Peas | Sow outdoors (spring) | Mar 31 – May 16 |
| Potatoes | Plant outdoors (spring) | Mar 31 – May 31 |
| Onions | Start seeds indoors (spring) | Feb 17 – Mar 16 |
| Onions | Transplant outdoors (spring) | Apr 17 – May 16 |
| Broccoli | Start seeds indoors (spring) | Mar 13 – Apr 16 |
| Broccoli | Transplant outdoors (spring) | Apr 17 – May 16 |
| Broccoli | Start seeds indoors (fall) | Jun 7 – Jun 17 |
| Broccoli | Transplant outdoors (fall) | Jul 7 – Jul 18 |
| Cabbage | Start seeds indoors (spring) | Mar 3 – Mar 31 |
| Cabbage | Transplant outdoors (spring) | Mar 31 – May 1 |
| Cabbage | Start seeds indoors (fall) | May 28 – Jun 27 |
| Cabbage | Transplant outdoors (fall) | Jun 27 – Jul 28 |
| Leaf lettuce | Sow outdoors (spring) | Mar 31 – Jun 16 |
| Leaf lettuce | Sow outdoors (fall) | Jun 27 – Aug 13 |
| Spinach | Sow outdoors (spring) | Mar 24 – May 7 |
| Spinach | Sow outdoors (fall) | Jul 14 – Aug 18 |
| Radishes | Sow outdoors (spring) | Mar 31 – May 21 |
| Radishes | Sow outdoors (fall) | Jun 27 – Aug 28 |
| Kale | Sow outdoors (spring) | Apr 17 – May 7 |
| Kale | Sow outdoors (fall) | Jun 20 – Jul 28 |
| Carrots | Sow outdoors (spring) | May 1 – Jun 16 |
| Carrots | Sow outdoors (fall) | May 28 – Jul 13 |
| Garlic | Plant outdoors (fall) | Sep 27 – Oct 28 |
Where these dates come from
ZIP code 57066 is matched to the NOAA station Tyndall, SD, 0.6 km away, at 1,420 ft elevation (4 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Tyndall, SD (used) | 1,420 ft | May 1 | Oct 7 |
| Niobrara, NE | 1,234 ft | Apr 25 | Oct 13 |
| Wagner, SD | 1,430 ft | Apr 29 | Oct 9 |
| Menno, SD | 1,332 ft | May 1 | Oct 4 |
Frost dates near Tyndall
- Springfield, SD 57062 · last May 1, first Oct 7
- Avon, SD 57315 · last May 1, first Oct 7
- Tabor, SD 57063 · last May 1, first Oct 7
- Scotland, SD 57059 · last May 1, first Oct 4
- Lesterville, SD 57040 · last May 1, first Oct 7
- Dante, SD 57329 · last Apr 29, first Oct 9
- Niobrara, NE 68760 · last Apr 25, first Oct 13
- Tripp, SD 57376 · last May 3, first Oct 6
Frequently asked questions
- When is the last frost in Tyndall, SD?
- For ZIP code 57066, the average last spring frost (32°F) is May 1, based on NOAA 1991-2020 climate normals for the Tyndall, SD weather station. There is a 1-in-10 chance of a frost after May 14.
- When is the first frost in Tyndall, SD?
- The average first fall frost (32°F) is October 7. There is a 1-in-10 chance of frost by September 24, so tender plants are at risk from that point on.
- How long is the growing season in 57066?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 158 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.