Frost dates for 57399Huron, SD
The average last spring frost in Huron is May 6 and the average first fall frost is October 2, giving a typical growing season of about 146 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 6
- Average first fall frost
- Oct 2
- Growing season
- 146 days
Safer after May 20 (1-in-10 risk)
Possible by Sep 19 (1-in-10 risk)
Last frost typically in 191 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 16 · May 28 | Sep 10 · Sep 24 · Oct 5 | 130 days | 100% |
| Frost / freeze (32°F) | Apr 23 · May 6 · May 20 | Sep 19 · Oct 2 · Oct 14 | 146 days | 100% |
| Hard freeze (28°F) | Apr 12 · Apr 27 · May 11 | Sep 26 · Oct 8 · Oct 22 | 165 days | 100% |
Planting calendar for Huron
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 5 – Jun 11 |
| Tomatoes | Transplant outdoors | May 22 – Jun 12 |
| Peppers | Start seeds indoors | Apr 5 – May 6 |
| Peppers | Transplant outdoors | Jun 5 – Jul 6 |
| Eggplant | Start seeds indoors | Apr 22 – May 21 |
| Eggplant | Transplant outdoors | Jun 5 – Jul 6 |
| Cucumbers | Sow outdoors | Jun 5 – Jun 22 |
| Summer squash | Sow outdoors | May 22 – Jul 6 |
| Winter squash & pumpkins | Sow outdoors | Jun 5 – Jul 6 |
| Snap beans | Sow outdoors | May 22 – Jul 15 |
| Sweet corn | Sow outdoors | May 22 – Jun 12 |
| Watermelon & cantaloupe | Sow outdoors | Jun 5 – Jul 6 |
| Okra | Sow outdoors | May 29 – Jun 21 |
| Peas | Sow outdoors (spring) | Apr 5 – May 21 |
| Potatoes | Plant outdoors (spring) | Apr 5 – Jun 5 |
| Onions | Start seeds indoors (spring) | Feb 22 – Mar 21 |
| Onions | Transplant outdoors (spring) | Apr 22 – May 21 |
| Broccoli | Start seeds indoors (spring) | Mar 18 – Apr 21 |
| Broccoli | Transplant outdoors (spring) | Apr 22 – May 21 |
| Broccoli | Start seeds indoors (fall) | Jun 2 – Jun 12 |
| Broccoli | Transplant outdoors (fall) | Jul 2 – Jul 13 |
| Cabbage | Start seeds indoors (spring) | Mar 8 – Apr 5 |
| Cabbage | Transplant outdoors (spring) | Apr 5 – May 6 |
| Cabbage | Start seeds indoors (fall) | May 23 – Jun 22 |
| Cabbage | Transplant outdoors (fall) | Jun 22 – Jul 23 |
| Leaf lettuce | Sow outdoors (spring) | Apr 5 – Jun 21 |
| Leaf lettuce | Sow outdoors (fall) | Jun 22 – Aug 8 |
| Spinach | Sow outdoors (spring) | Mar 29 – May 12 |
| Spinach | Sow outdoors (fall) | Jul 9 – Aug 13 |
| Radishes | Sow outdoors (spring) | Apr 5 – May 26 |
| Radishes | Sow outdoors (fall) | Jun 22 – Aug 23 |
| Kale | Sow outdoors (spring) | Apr 22 – May 12 |
| Kale | Sow outdoors (fall) | Jun 15 – Jul 23 |
| Carrots | Sow outdoors (spring) | May 6 – Jun 21 |
| Carrots | Sow outdoors (fall) | May 23 – Jul 8 |
| Garlic | Plant outdoors (fall) | Sep 22 – Oct 23 |
Where these dates come from
ZIP code 57399 is matched to the NOAA station Huron Rgnl Ap, SD, 3.9 km away, at 1,280 ft elevation (0 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Huron Rgnl Ap, SD (used) | 1,280 ft | May 6 | Oct 2 |
| Forestburg 4 Nne, SD | 1,277 ft | May 9 | Sep 28 |
| Wessington Springs, SD | 1,715 ft | May 2 | Oct 8 |
| De Smet, SD | 1,705 ft | May 5 | Oct 4 |
Frost dates near Huron
- Huron, SD 57350 · last May 6, first Oct 2
- Cavour, SD 57324 · last May 6, first Oct 2
- Virgil, SD 57379 · last May 6, first Oct 2
- Wolsey, SD 57384 · last May 6, first Oct 2
- Yale, SD 57386 · last May 6, first Oct 2
- Alpena, SD 57312 · last May 9, first Sep 28
- Iroquois, SD 57353 · last May 6, first Oct 2
- Hitchcock, SD 57348 · last May 6, first Oct 2
Frequently asked questions
- When is the last frost in Huron, SD?
- For ZIP code 57399, the average last spring frost (32°F) is May 6, based on NOAA 1991-2020 climate normals for the Huron Rgnl Ap, SD weather station. There is a 1-in-10 chance of a frost after May 20.
- When is the first frost in Huron, SD?
- The average first fall frost (32°F) is October 2. 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 57399?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 146 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.