Frost dates for 57638Lemmon, SD
The average last spring frost in Lemmon is May 10 and the average first fall frost is September 30, giving a typical growing season of about 142 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 10
- Average first fall frost
- Sep 30
- Growing season
- 142 days
Safer after May 24 (1-in-10 risk)
Possible by Sep 18 (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 20 · Jun 2 | Sep 9 · Sep 22 · Oct 3 | 122 days | 100% |
| Frost / freeze (32°F) | Apr 30 · May 10 · May 24 | Sep 18 · Sep 30 · Oct 12 | 142 days | 100% |
| Hard freeze (28°F) | Apr 17 · May 1 · May 14 | Sep 25 · Oct 9 · Oct 22 | 160 days | 100% |
Planting calendar for Lemmon
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 10 |
| 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 20 |
| Summer squash | Sow outdoors | May 26 – Jul 10 |
| Winter squash & pumpkins | Sow outdoors | Jun 9 – Jul 10 |
| Snap beans | Sow outdoors | May 26 – Jul 13 |
| Sweet corn | Sow outdoors | May 26 – Jun 10 |
| 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) | May 31 – Jun 10 |
| Broccoli | Transplant outdoors (fall) | Jun 30 – Jul 11 |
| Cabbage | Start seeds indoors (spring) | Mar 12 – Apr 9 |
| Cabbage | Transplant outdoors (spring) | Apr 9 – May 10 |
| Cabbage | Start seeds indoors (fall) | May 21 – Jun 20 |
| Cabbage | Transplant outdoors (fall) | Jun 20 – Jul 21 |
| Leaf lettuce | Sow outdoors (spring) | Apr 9 – Jun 25 |
| Leaf lettuce | Sow outdoors (fall) | Jun 20 – Aug 6 |
| Spinach | Sow outdoors (spring) | Apr 2 – May 16 |
| Spinach | Sow outdoors (fall) | Jul 7 – Aug 11 |
| Radishes | Sow outdoors (spring) | Apr 9 – May 30 |
| Radishes | Sow outdoors (fall) | Jun 20 – Aug 21 |
| Kale | Sow outdoors (spring) | Apr 26 – May 16 |
| Kale | Sow outdoors (fall) | Jun 13 – Jul 21 |
| Carrots | Sow outdoors (spring) | May 10 – Jun 25 |
| Carrots | Sow outdoors (fall) | May 21 – Jul 6 |
| Garlic | Plant outdoors (fall) | Sep 20 – Oct 21 |
Where these dates come from
ZIP code 57638 is matched to the NOAA station Lemmon, SD, 3.8 km away, at 2,567 ft elevation (58 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Lemmon, SD (used) | 2,567 ft | May 10 | Sep 30 |
| Shadehill Rsvr, SD | 2,450 ft | May 16 | Sep 24 |
| Hettinger Exp Stn, ND | 2,703 ft | May 21 | Sep 21 |
| Hettinger Muni Ap, ND | 2,705 ft | May 24 | Sep 18 |
Frost dates near Lemmon
- Keldron, SD 57634 · last May 10, first Sep 30
- Morristown, SD 57645 · last May 20, first Sep 23
- Lodgepole, SD 57640 · last May 21, first Sep 21
- Hettinger, ND 58639 · last May 24, first Sep 18
- Bison, SD 57620 · last May 10, first Oct 1
- Mott, ND 58646 · last May 16, first Sep 25
- Watauga, SD 57660 · last May 9, first Sep 30
- New Leipzig, ND 58562 · last May 20, first Sep 23
Frequently asked questions
- When is the last frost in Lemmon, SD?
- For ZIP code 57638, the average last spring frost (32°F) is May 10, based on NOAA 1991-2020 climate normals for the Lemmon, SD weather station. There is a 1-in-10 chance of a frost after May 24.
- When is the first frost in Lemmon, SD?
- The average first fall frost (32°F) is September 30. There is a 1-in-10 chance of frost by September 18, so tender plants are at risk from that point on.
- How long is the growing season in 57638?
- 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.