Frost dates for 57278Willow Lake, SD
The average last spring frost in Willow Lake is May 5 and the average first fall frost is October 5, giving a typical growing season of about 153 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 5
- Average first fall frost
- Oct 5
- Growing season
- 153 days
Safer after May 18 (1-in-10 risk)
Possible by Sep 24 (1-in-10 risk)
Last frost typically in 190 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 2 · May 13 · May 26 | Sep 16 · Sep 27 · Oct 9 | 135 days | 100% |
| Frost / freeze (32°F) | Apr 22 · May 5 · May 18 | Sep 24 · Oct 5 · Oct 19 | 153 days | 100% |
| Hard freeze (28°F) | Apr 12 · Apr 26 · May 8 | Oct 1 · Oct 15 · Oct 27 | 170 days | 100% |
Planting calendar for Willow Lake
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 15 |
| 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 25 |
| Summer squash | Sow outdoors | May 21 – Jul 5 |
| Winter squash & pumpkins | Sow outdoors | Jun 4 – Jul 5 |
| Snap beans | Sow outdoors | May 21 – Jul 18 |
| Sweet corn | Sow outdoors | May 21 – Jun 15 |
| 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 5 – Jun 15 |
| Broccoli | Transplant outdoors (fall) | Jul 5 – Jul 16 |
| Cabbage | Start seeds indoors (spring) | Mar 7 – Apr 4 |
| Cabbage | Transplant outdoors (spring) | Apr 4 – May 5 |
| Cabbage | Start seeds indoors (fall) | May 26 – Jun 25 |
| Cabbage | Transplant outdoors (fall) | Jun 25 – Jul 26 |
| Leaf lettuce | Sow outdoors (spring) | Apr 4 – Jun 20 |
| Leaf lettuce | Sow outdoors (fall) | Jun 25 – Aug 11 |
| Spinach | Sow outdoors (spring) | Mar 28 – May 11 |
| Spinach | Sow outdoors (fall) | Jul 12 – Aug 16 |
| Radishes | Sow outdoors (spring) | Apr 4 – May 25 |
| Radishes | Sow outdoors (fall) | Jun 25 – Aug 26 |
| Kale | Sow outdoors (spring) | Apr 21 – May 11 |
| Kale | Sow outdoors (fall) | Jun 18 – Jul 26 |
| Carrots | Sow outdoors (spring) | May 5 – Jun 20 |
| Carrots | Sow outdoors (fall) | May 26 – Jul 11 |
| Garlic | Plant outdoors (fall) | Sep 25 – Oct 26 |
Where these dates come from
ZIP code 57278 is matched to the NOAA station Clark, SD, 28.7 km away, at 1,804 ft elevation (19 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Clark, SD (used) | 1,804 ft | May 5 | Oct 5 |
| Clark No2, SD | 1,814 ft | May 5 | Oct 5 |
| De Smet, SD | 1,705 ft | May 5 | Oct 4 |
| Arlington 1 W, SD | 1,824 ft | May 3 | Oct 2 |
Frost dates near Willow Lake
- Vienna, SD 57271 · last May 5, first Oct 5
- Bryant, SD 57221 · last May 5, first Oct 4
- Carpenter, SD 57322 · last May 5, first Oct 5
- Erwin, SD 57233 · last May 5, first Oct 4
- Clark, SD 57225 · last May 5, first Oct 5
- De Smet, SD 57231 · last May 5, first Oct 4
- Yale, SD 57386 · last May 6, first Oct 2
- Hazel, SD 57242 · last May 7, first Sep 30
Frequently asked questions
- When is the last frost in Willow Lake, SD?
- For ZIP code 57278, the average last spring frost (32°F) is May 5, based on NOAA 1991-2020 climate normals for the Clark, SD weather station. There is a 1-in-10 chance of a frost after May 18.
- When is the first frost in Willow Lake, SD?
- The average first fall frost (32°F) is October 5. 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 57278?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 153 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.