Frost dates for 56140Ihlen, MN
The average last spring frost in Ihlen is May 4 and the average first fall frost is October 2, giving a typical growing season of about 152 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 4
- Average first fall frost
- Oct 2
- Growing season
- 152 days
Safer after May 19 (1-in-10 risk)
Possible by Sep 20 (1-in-10 risk)
Last frost typically in 182 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 14 · May 29 | Sep 11 · Sep 25 · Oct 7 | 133 days | 100% |
| Frost / freeze (32°F) | Apr 21 · May 4 · May 19 | Sep 20 · Oct 2 · Oct 16 | 152 days | 100% |
| Hard freeze (28°F) | Apr 10 · Apr 25 · May 8 | Sep 27 · Oct 12 · Oct 25 | 170 days | 100% |
Planting calendar for Ihlen
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 3 – Jun 9 |
| Tomatoes | Transplant outdoors | May 20 – Jun 12 |
| Peppers | Start seeds indoors | Apr 3 – May 4 |
| Peppers | Transplant outdoors | Jun 3 – Jul 4 |
| Eggplant | Start seeds indoors | Apr 20 – May 19 |
| Eggplant | Transplant outdoors | Jun 3 – Jul 4 |
| Cucumbers | Sow outdoors | Jun 3 – Jun 22 |
| Summer squash | Sow outdoors | May 20 – Jul 4 |
| Winter squash & pumpkins | Sow outdoors | Jun 3 – Jul 4 |
| Snap beans | Sow outdoors | May 20 – Jul 15 |
| Sweet corn | Sow outdoors | May 20 – Jun 12 |
| Watermelon & cantaloupe | Sow outdoors | Jun 3 – Jul 4 |
| Okra | Sow outdoors | May 27 – Jun 19 |
| Peas | Sow outdoors (spring) | Apr 3 – May 19 |
| Potatoes | Plant outdoors (spring) | Apr 3 – Jun 3 |
| Onions | Start seeds indoors (spring) | Feb 20 – Mar 19 |
| Onions | Transplant outdoors (spring) | Apr 20 – May 19 |
| Broccoli | Start seeds indoors (spring) | Mar 16 – Apr 19 |
| Broccoli | Transplant outdoors (spring) | Apr 20 – May 19 |
| Broccoli | Start seeds indoors (fall) | Jun 2 – Jun 12 |
| Broccoli | Transplant outdoors (fall) | Jul 2 – Jul 13 |
| Cabbage | Start seeds indoors (spring) | Mar 6 – Apr 3 |
| Cabbage | Transplant outdoors (spring) | Apr 3 – May 4 |
| Cabbage | Start seeds indoors (fall) | May 23 – Jun 22 |
| Cabbage | Transplant outdoors (fall) | Jun 22 – Jul 23 |
| Leaf lettuce | Sow outdoors (spring) | Apr 3 – Jun 19 |
| Leaf lettuce | Sow outdoors (fall) | Jun 22 – Aug 8 |
| Spinach | Sow outdoors (spring) | Mar 27 – May 10 |
| Spinach | Sow outdoors (fall) | Jul 9 – Aug 13 |
| Radishes | Sow outdoors (spring) | Apr 3 – May 24 |
| Radishes | Sow outdoors (fall) | Jun 22 – Aug 23 |
| Kale | Sow outdoors (spring) | Apr 20 – May 10 |
| Kale | Sow outdoors (fall) | Jun 15 – Jul 23 |
| Carrots | Sow outdoors (spring) | May 4 – Jun 19 |
| Carrots | Sow outdoors (fall) | May 23 – Jul 8 |
| Garlic | Plant outdoors (fall) | Sep 22 – Oct 23 |
Where these dates come from
ZIP code 56140 is matched to the NOAA station Pipestone, MN, 12.3 km away, at 1,705 ft elevation (55 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Pipestone, MN (used) | 1,705 ft | May 4 | Oct 2 |
| Flandreau, SD | 1,567 ft | May 5 | Oct 1 |
| Sioux Falls 14 Nne, SD | 1,594 ft | May 1 | Oct 4 |
| Lake Wilson, MN | 1,653 ft | May 7 | Sep 29 |
Frost dates near Ihlen
- Jasper, MN 56144 · last May 4, first Oct 2
- Pipestone, MN 56164 · last May 4, first Oct 2
- Hardwick, MN 56134 · last May 4, first Oct 2
- Edgerton, MN 56128 · last May 7, first Sep 29
- Trent, SD 57065 · last May 5, first Oct 1
- Woodstock, MN 56186 · last May 7, first Sep 29
- Holland, MN 56139 · last May 4, first Oct 2
- Egan, SD 57024 · last May 5, first Oct 1
Frequently asked questions
- When is the last frost in Ihlen, MN?
- For ZIP code 56140, the average last spring frost (32°F) is May 4, based on NOAA 1991-2020 climate normals for the Pipestone, MN weather station. There is a 1-in-10 chance of a frost after May 19.
- When is the first frost in Ihlen, MN?
- The average first fall frost (32°F) is October 2. There is a 1-in-10 chance of frost by September 20, so tender plants are at risk from that point on.
- How long is the growing season in 56140?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 152 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.