Frost dates for 57649Prairie City, SD
The average last spring frost in Prairie City is May 10 and the average first fall frost is October 1, giving a typical growing season of about 144 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 10
- Average first fall frost
- Oct 1
- Growing season
- 144 days
Safer after May 24 (1-in-10 risk)
Possible by Sep 16 (1-in-10 risk)
Last frost typically in 195 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 8 · May 19 · Jun 1 | Sep 9 · Sep 24 · Oct 5 | 125 days | 100% |
| Frost / freeze (32°F) | Apr 30 · May 10 · May 24 | Sep 16 · Oct 1 · Oct 15 | 144 days | 100% |
| Hard freeze (28°F) | Apr 16 · May 1 · May 13 | Sep 25 · Oct 9 · Oct 24 | 161 days | 100% |
Planting calendar for Prairie City
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 9 – Jun 15 |
| Tomatoes | Transplant outdoors | May 26 – Jun 11 |
| Peppers | Start seeds indoors | Apr 9 – May 10 |
| Peppers | Transplant outdoors | Jun 9 – Jul 10 |
| Eggplant | Start seeds indoors | Apr 26 – May 25 |
| Eggplant | Transplant outdoors | Jun 9 – Jul 10 |
| Cucumbers | Sow outdoors | Jun 9 – Jun 21 |
| Summer squash | Sow outdoors | May 26 – Jul 10 |
| Winter squash & pumpkins | Sow outdoors | Jun 9 – Jul 10 |
| Snap beans | Sow outdoors | May 26 – Jul 14 |
| Sweet corn | Sow outdoors | May 26 – Jun 11 |
| Watermelon & cantaloupe | Sow outdoors | Jun 9 – Jul 10 |
| Okra | Sow outdoors | Jun 2 – Jun 25 |
| Peas | Sow outdoors (spring) | Apr 9 – May 25 |
| Potatoes | Plant outdoors (spring) | Apr 9 – Jun 9 |
| Onions | Start seeds indoors (spring) | Feb 26 – Mar 25 |
| Onions | Transplant outdoors (spring) | Apr 26 – May 25 |
| Broccoli | Start seeds indoors (spring) | Mar 22 – Apr 25 |
| Broccoli | Transplant outdoors (spring) | Apr 26 – May 25 |
| Broccoli | Start seeds indoors (fall) | Jun 1 – Jun 11 |
| Broccoli | Transplant outdoors (fall) | Jul 1 – Jul 12 |
| Cabbage | Start seeds indoors (spring) | Mar 12 – Apr 9 |
| Cabbage | Transplant outdoors (spring) | Apr 9 – May 10 |
| Cabbage | Start seeds indoors (fall) | May 22 – Jun 21 |
| Cabbage | Transplant outdoors (fall) | Jun 21 – Jul 22 |
| Leaf lettuce | Sow outdoors (spring) | Apr 9 – Jun 25 |
| Leaf lettuce | Sow outdoors (fall) | Jun 21 – Aug 7 |
| Spinach | Sow outdoors (spring) | Apr 2 – May 16 |
| Spinach | Sow outdoors (fall) | Jul 8 – Aug 12 |
| Radishes | Sow outdoors (spring) | Apr 9 – May 30 |
| Radishes | Sow outdoors (fall) | Jun 21 – Aug 22 |
| Kale | Sow outdoors (spring) | Apr 26 – May 16 |
| Kale | Sow outdoors (fall) | Jun 14 – Jul 22 |
| Carrots | Sow outdoors (spring) | May 10 – Jun 25 |
| Carrots | Sow outdoors (fall) | May 22 – Jul 7 |
| Garlic | Plant outdoors (fall) | Sep 21 – Oct 22 |
Where these dates come from
ZIP code 57649 is matched to the NOAA station Bison, SD, 27.4 km away, at 2,780 ft elevation (88 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Bison, SD (used) | 2,780 ft | May 10 | Oct 1 |
| Lodgepole 5Sw, SD | 2,570 ft | May 30 | Sep 11 |
| Ralph 1 N, SD | 2,790 ft | May 18 | Sep 23 |
| Buffalo 13 Ese, SD | 2,883 ft | May 20 | Sep 19 |
Frost dates near Prairie City
- Reva, SD 57651 · last May 20, first Sep 19
- Bison, SD 57620 · last May 10, first Oct 1
- Lodgepole, SD 57640 · last May 21, first Sep 21
- Ralph, SD 57650 · last May 16, first Sep 26
- Meadow, SD 57644 · last May 10, first Oct 1
- Ludlow, SD 57755 · last May 16, first Sep 26
- Hettinger, ND 58639 · last May 24, first Sep 18
- Reeder, ND 58649 · last May 24, first Sep 18
Frequently asked questions
- When is the last frost in Prairie City, SD?
- For ZIP code 57649, the average last spring frost (32°F) is May 10, based on NOAA 1991-2020 climate normals for the Bison, SD weather station. There is a 1-in-10 chance of a frost after May 24.
- When is the first frost in Prairie City, SD?
- The average first fall frost (32°F) is October 1. There is a 1-in-10 chance of frost by September 16, so tender plants are at risk from that point on.
- How long is the growing season in 57649?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 144 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.