Frost dates for 57344Harrison, SD
The average last spring frost in Harrison is May 3 and the average first fall frost is October 6, giving a typical growing season of about 157 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 3
- Average first fall frost
- Oct 6
- Growing season
- 157 days
Safer after May 18 (1-in-10 risk)
Possible by Sep 23 (1-in-10 risk)
Last frost typically in 188 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 30 · May 12 · May 26 | Sep 16 · Sep 28 · Oct 10 | 139 days | 100% |
| Frost / freeze (32°F) | Apr 17 · May 3 · May 18 | Sep 23 · Oct 6 · Oct 21 | 157 days | 100% |
| Hard freeze (28°F) | Apr 6 · Apr 21 · May 7 | Oct 1 · Oct 16 · Oct 30 | 176 days | 100% |
Planting calendar for Harrison
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 2 – Jun 8 |
| Tomatoes | Transplant outdoors | May 19 – Jun 16 |
| Peppers | Start seeds indoors | Apr 2 – May 3 |
| Peppers | Transplant outdoors | Jun 2 – Jul 3 |
| Eggplant | Start seeds indoors | Apr 19 – May 18 |
| Eggplant | Transplant outdoors | Jun 2 – Jul 3 |
| Cucumbers | Sow outdoors | Jun 2 – Jun 26 |
| Summer squash | Sow outdoors | May 19 – Jul 3 |
| Winter squash & pumpkins | Sow outdoors | Jun 2 – Jul 3 |
| Snap beans | Sow outdoors | May 19 – Jul 19 |
| Sweet corn | Sow outdoors | May 19 – Jun 16 |
| Watermelon & cantaloupe | Sow outdoors | Jun 2 – Jul 3 |
| Okra | Sow outdoors | May 26 – Jun 18 |
| Peas | Sow outdoors (spring) | Apr 2 – May 18 |
| Potatoes | Plant outdoors (spring) | Apr 2 – Jun 2 |
| Onions | Start seeds indoors (spring) | Feb 19 – Mar 18 |
| Onions | Transplant outdoors (spring) | Apr 19 – May 18 |
| Broccoli | Start seeds indoors (spring) | Mar 15 – Apr 18 |
| Broccoli | Transplant outdoors (spring) | Apr 19 – May 18 |
| Broccoli | Start seeds indoors (fall) | Jun 6 – Jun 16 |
| Broccoli | Transplant outdoors (fall) | Jul 6 – Jul 17 |
| Cabbage | Start seeds indoors (spring) | Mar 5 – Apr 2 |
| Cabbage | Transplant outdoors (spring) | Apr 2 – May 3 |
| Cabbage | Start seeds indoors (fall) | May 27 – Jun 26 |
| Cabbage | Transplant outdoors (fall) | Jun 26 – Jul 27 |
| Leaf lettuce | Sow outdoors (spring) | Apr 2 – Jun 18 |
| Leaf lettuce | Sow outdoors (fall) | Jun 26 – Aug 12 |
| Spinach | Sow outdoors (spring) | Mar 26 – May 9 |
| Spinach | Sow outdoors (fall) | Jul 13 – Aug 17 |
| Radishes | Sow outdoors (spring) | Apr 2 – May 23 |
| Radishes | Sow outdoors (fall) | Jun 26 – Aug 27 |
| Kale | Sow outdoors (spring) | Apr 19 – May 9 |
| Kale | Sow outdoors (fall) | Jun 19 – Jul 27 |
| Carrots | Sow outdoors (spring) | May 3 – Jun 18 |
| Carrots | Sow outdoors (fall) | May 27 – Jul 12 |
| Garlic | Plant outdoors (fall) | Sep 26 – Oct 27 |
Where these dates come from
ZIP code 57344 is matched to the NOAA station Armour, SD, 19.4 km away, at 1,510 ft elevation (91 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Armour, SD (used) | 1,510 ft | May 3 | Oct 6 |
| White Lake, SD | 1,629 ft | May 3 | Oct 5 |
| Pickstown, SD | 1,490 ft | Apr 30 | Oct 13 |
| Wagner, SD | 1,430 ft | Apr 29 | Oct 9 |
Frost dates near Harrison
- New Holland, SD 57364 · last May 3, first Oct 6
- Corsica, SD 57328 · last May 3, first Oct 6
- Stickney, SD 57375 · last May 3, first Oct 5
- Armour, SD 57313 · last May 3, first Oct 6
- Geddes, SD 57342 · last Apr 30, first Oct 13
- Lake Andes, SD 57356 · last Apr 30, first Oct 13
- Platte, SD 57369 · last Apr 30, first Oct 8
- Plankinton, SD 57368 · last May 3, first Oct 5
Frequently asked questions
- When is the last frost in Harrison, SD?
- For ZIP code 57344, the average last spring frost (32°F) is May 3, based on NOAA 1991-2020 climate normals for the Armour, SD weather station. There is a 1-in-10 chance of a frost after May 18.
- When is the first frost in Harrison, SD?
- The average first fall frost (32°F) is October 6. There is a 1-in-10 chance of frost by September 23, so tender plants are at risk from that point on.
- How long is the growing season in 57344?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 157 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.