Frost dates for 57466Onaka, SD
The average last spring frost in Onaka is May 7 and the average first fall frost is October 3, giving a typical growing season of about 148 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 7
- Average first fall frost
- Oct 3
- Growing season
- 148 days
Safer after May 20 (1-in-10 risk)
Possible by Sep 19 (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 5 · May 16 · May 28 | Sep 13 · Sep 25 · Oct 6 | 131 days | 100% |
| Frost / freeze (32°F) | Apr 24 · May 7 · May 20 | Sep 19 · Oct 3 · Oct 16 | 148 days | 100% |
| Hard freeze (28°F) | Apr 14 · Apr 29 · May 10 | Sep 30 · Oct 12 · Oct 24 | 166 days | 100% |
Planting calendar for Onaka
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 6 – Jun 12 |
| Tomatoes | Transplant outdoors | May 23 – Jun 13 |
| Peppers | Start seeds indoors | Apr 6 – May 7 |
| Peppers | Transplant outdoors | Jun 6 – Jul 7 |
| Eggplant | Start seeds indoors | Apr 23 – May 22 |
| Eggplant | Transplant outdoors | Jun 6 – Jul 7 |
| Cucumbers | Sow outdoors | Jun 6 – Jun 23 |
| Summer squash | Sow outdoors | May 23 – Jul 7 |
| Winter squash & pumpkins | Sow outdoors | Jun 6 – Jul 7 |
| Snap beans | Sow outdoors | May 23 – Jul 16 |
| Sweet corn | Sow outdoors | May 23 – Jun 13 |
| Watermelon & cantaloupe | Sow outdoors | Jun 6 – Jul 7 |
| Okra | Sow outdoors | May 30 – Jun 22 |
| Peas | Sow outdoors (spring) | Apr 6 – May 22 |
| Potatoes | Plant outdoors (spring) | Apr 6 – Jun 6 |
| Onions | Start seeds indoors (spring) | Feb 23 – Mar 22 |
| Onions | Transplant outdoors (spring) | Apr 23 – May 22 |
| Broccoli | Start seeds indoors (spring) | Mar 19 – Apr 22 |
| Broccoli | Transplant outdoors (spring) | Apr 23 – May 22 |
| Broccoli | Start seeds indoors (fall) | Jun 3 – Jun 13 |
| Broccoli | Transplant outdoors (fall) | Jul 3 – Jul 14 |
| Cabbage | Start seeds indoors (spring) | Mar 9 – Apr 6 |
| Cabbage | Transplant outdoors (spring) | Apr 6 – May 7 |
| Cabbage | Start seeds indoors (fall) | May 24 – Jun 23 |
| Cabbage | Transplant outdoors (fall) | Jun 23 – Jul 24 |
| Leaf lettuce | Sow outdoors (spring) | Apr 6 – Jun 22 |
| Leaf lettuce | Sow outdoors (fall) | Jun 23 – Aug 9 |
| Spinach | Sow outdoors (spring) | Mar 30 – May 13 |
| Spinach | Sow outdoors (fall) | Jul 10 – Aug 14 |
| Radishes | Sow outdoors (spring) | Apr 6 – May 27 |
| Radishes | Sow outdoors (fall) | Jun 23 – Aug 24 |
| Kale | Sow outdoors (spring) | Apr 23 – May 13 |
| Kale | Sow outdoors (fall) | Jun 16 – Jul 24 |
| Carrots | Sow outdoors (spring) | May 7 – Jun 22 |
| Carrots | Sow outdoors (fall) | May 24 – Jul 9 |
| Garlic | Plant outdoors (fall) | Sep 23 – Oct 24 |
Where these dates come from
ZIP code 57466 is matched to the NOAA station Roscoe, SD, 30 km away, at 1,835 ft elevation (25 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Roscoe, SD (used) | 1,835 ft | May 7 | Oct 3 |
| Faulkton 1 Nw, SD | 1,597 ft | May 10 | Sep 28 |
| Highmore 23 N, SD | 1,870 ft | May 14 | Sep 29 |
| Ipswich, SD | 1,547 ft | May 8 | Sep 29 |
Frost dates near Onaka
- Tolstoy, SD 57475 · last May 7, first Oct 2
- Seneca, SD 57473 · last May 14, first Sep 29
- Faulkton, SD 57438 · last May 10, first Sep 28
- Hoven, SD 57450 · last May 7, first Oct 2
- Roscoe, SD 57471 · last May 7, first Oct 3
- Lebanon, SD 57455 · last May 7, first Oct 2
- Bowdle, SD 57428 · last May 7, first Oct 3
- Java, SD 57452 · last May 8, first Oct 1
Frequently asked questions
- When is the last frost in Onaka, SD?
- For ZIP code 57466, the average last spring frost (32°F) is May 7, based on NOAA 1991-2020 climate normals for the Roscoe, SD weather station. There is a 1-in-10 chance of a frost after May 20.
- When is the first frost in Onaka, SD?
- The average first fall frost (32°F) is October 3. There is a 1-in-10 chance of frost by September 19, so tender plants are at risk from that point on.
- How long is the growing season in 57466?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 148 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.