Frost dates for 57345Highmore, SD
The average last spring frost in Highmore is May 12 and the average first fall frost is October 1, giving a typical growing season of about 142 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 12
- Average first fall frost
- Oct 1
- Growing season
- 142 days
Safer after May 28 (1-in-10 risk)
Possible by Sep 17 (1-in-10 risk)
Last frost typically in 197 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 7 · May 21 · Jun 5 | Sep 10 · Sep 22 · Oct 5 | 124 days | 100% |
| Frost / freeze (32°F) | Apr 28 · May 12 · May 28 | Sep 17 · Oct 1 · Oct 14 | 142 days | 100% |
| Hard freeze (28°F) | Apr 14 · May 2 · May 17 | Sep 25 · Oct 10 · Oct 25 | 158 days | 100% |
Planting calendar for Highmore
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 11 – Jun 17 |
| Tomatoes | Transplant outdoors | May 28 – Jun 11 |
| Peppers | Start seeds indoors | Apr 11 – May 12 |
| Peppers | Transplant outdoors | Jun 11 – Jul 12 |
| Eggplant | Start seeds indoors | Apr 28 – May 27 |
| Eggplant | Transplant outdoors | Jun 11 – Jul 12 |
| Cucumbers | Sow outdoors | Jun 11 – Jun 21 |
| Summer squash | Sow outdoors | May 28 – Jul 12 |
| Winter squash & pumpkins | Sow outdoors | Jun 11 – Jul 12 |
| Snap beans | Sow outdoors | May 28 – Jul 14 |
| Sweet corn | Sow outdoors | May 28 – Jun 11 |
| Watermelon & cantaloupe | Sow outdoors | Jun 11 – Jul 12 |
| Okra | Sow outdoors | Jun 4 – Jun 27 |
| Peas | Sow outdoors (spring) | Apr 11 – May 27 |
| Potatoes | Plant outdoors (spring) | Apr 11 – Jun 11 |
| Onions | Start seeds indoors (spring) | Feb 28 – Mar 27 |
| Onions | Transplant outdoors (spring) | Apr 28 – May 27 |
| Broccoli | Start seeds indoors (spring) | Mar 24 – Apr 27 |
| Broccoli | Transplant outdoors (spring) | Apr 28 – May 27 |
| Broccoli | Start seeds indoors (fall) | Jun 1 – Jun 11 |
| Broccoli | Transplant outdoors (fall) | Jul 1 – Jul 12 |
| Cabbage | Start seeds indoors (spring) | Mar 14 – Apr 11 |
| Cabbage | Transplant outdoors (spring) | Apr 11 – May 12 |
| Cabbage | Start seeds indoors (fall) | May 22 – Jun 21 |
| Cabbage | Transplant outdoors (fall) | Jun 21 – Jul 22 |
| Leaf lettuce | Sow outdoors (spring) | Apr 11 – Jun 27 |
| Leaf lettuce | Sow outdoors (fall) | Jun 21 – Aug 7 |
| Spinach | Sow outdoors (spring) | Apr 4 – May 18 |
| Spinach | Sow outdoors (fall) | Jul 8 – Aug 12 |
| Radishes | Sow outdoors (spring) | Apr 11 – Jun 1 |
| Radishes | Sow outdoors (fall) | Jun 21 – Aug 22 |
| Kale | Sow outdoors (spring) | Apr 28 – May 18 |
| Kale | Sow outdoors (fall) | Jun 14 – Jul 22 |
| Carrots | Sow outdoors (spring) | May 12 – Jun 27 |
| Carrots | Sow outdoors (fall) | May 22 – Jul 7 |
| Garlic | Plant outdoors (fall) | Sep 21 – Oct 22 |
Where these dates come from
ZIP code 57345 is matched to the NOAA station Highmore 1 W, SD, 1.2 km away, at 1,888 ft elevation (25 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Highmore 1 W, SD (used) | 1,888 ft | May 12 | Oct 1 |
| Stephan 2 Nw, SD | 1,805 ft | May 10 | Sep 29 |
| Harrold 12 Ssw, SD | 1,701 ft | May 17 | Sep 24 |
| Highmore 23 N, SD | 1,870 ft | May 14 | Sep 29 |
Frost dates near Highmore
- Holabird, SD 57540 · last May 12, first Oct 1
- Ree Heights, SD 57371 · last May 3, first Oct 3
- Harrold, SD 57536 · last May 17, first Sep 24
- Stephan, SD 57346 · last May 10, first Sep 29
- Miller, SD 57362 · last May 3, first Oct 3
- Blunt, SD 57522 · last May 17, first Sep 24
- Orient, SD 57467 · last May 10, first Sep 28
- Saint Lawrence, SD 57373 · last May 3, first Oct 3
Frequently asked questions
- When is the last frost in Highmore, SD?
- For ZIP code 57345, the average last spring frost (32°F) is May 12, based on NOAA 1991-2020 climate normals for the Highmore 1 W, SD weather station. There is a 1-in-10 chance of a frost after May 28.
- When is the first frost in Highmore, SD?
- The average first fall frost (32°F) is October 1. There is a 1-in-10 chance of frost by September 17, so tender plants are at risk from that point on.
- How long is the growing season in 57345?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 142 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.