Frost dates for 49740Harbor Springs, MI
The average last spring frost in Harbor Springs is May 15 and the average first fall frost is October 16, giving a typical growing season of about 152 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 15
- Average first fall frost
- Oct 16
- Growing season
- 152 days
Safer after May 30 (1-in-10 risk)
Possible by Sep 30 (1-in-10 risk)
Last frost typically in 194 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 11 · May 28 · Jun 11 | Sep 17 · Oct 3 · Oct 20 | 126 days | 100% |
| Frost / freeze (32°F) | Apr 30 · May 15 · May 30 | Sep 30 · Oct 16 · Nov 1 | 152 days | 100% |
| Hard freeze (28°F) | Apr 20 · May 1 · May 19 | Oct 10 · Oct 31 · Nov 15 | 178 days | 100% |
Planting calendar for Harbor Springs
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 14 – Jun 20 |
| Tomatoes | Transplant outdoors | May 31 – Jun 26 |
| Peppers | Start seeds indoors | Apr 14 – May 15 |
| Peppers | Transplant outdoors | Jun 14 – Jul 15 |
| Eggplant | Start seeds indoors | May 1 – May 30 |
| Eggplant | Transplant outdoors | Jun 14 – Jul 15 |
| Cucumbers | Sow outdoors | Jun 14 – Jul 6 |
| Summer squash | Sow outdoors | May 31 – Jul 15 |
| Winter squash & pumpkins | Sow outdoors | Jun 14 – Jul 15 |
| Snap beans | Sow outdoors | May 31 – Jul 29 |
| Sweet corn | Sow outdoors | May 31 – Jun 26 |
| Watermelon & cantaloupe | Sow outdoors | Jun 14 – Jul 15 |
| Okra | Sow outdoors | Jun 7 – Jun 30 |
| Peas | Sow outdoors (spring) | Apr 14 – May 30 |
| Potatoes | Plant outdoors (spring) | Apr 14 – Jun 14 |
| Onions | Start seeds indoors (spring) | Mar 3 – Mar 30 |
| Onions | Transplant outdoors (spring) | May 1 – May 30 |
| Broccoli | Start seeds indoors (spring) | Mar 27 – Apr 30 |
| Broccoli | Transplant outdoors (spring) | May 1 – May 30 |
| Broccoli | Start seeds indoors (fall) | Jun 16 – Jun 26 |
| Broccoli | Transplant outdoors (fall) | Jul 16 – Jul 27 |
| Cabbage | Start seeds indoors (spring) | Mar 17 – Apr 14 |
| Cabbage | Transplant outdoors (spring) | Apr 14 – May 15 |
| Cabbage | Start seeds indoors (fall) | Jun 6 – Jul 6 |
| Cabbage | Transplant outdoors (fall) | Jul 6 – Aug 6 |
| Leaf lettuce | Sow outdoors (spring) | Apr 14 – Jun 30 |
| Leaf lettuce | Sow outdoors (fall) | Jul 6 – Aug 22 |
| Spinach | Sow outdoors (spring) | Apr 7 – May 21 |
| Spinach | Sow outdoors (fall) | Jul 23 – Aug 27 |
| Radishes | Sow outdoors (spring) | Apr 14 – Jun 4 |
| Radishes | Sow outdoors (fall) | Jul 6 – Sep 6 |
| Kale | Sow outdoors (spring) | May 1 – May 21 |
| Kale | Sow outdoors (fall) | Jun 29 – Aug 6 |
| Carrots | Sow outdoors (spring) | May 15 – Jun 30 |
| Carrots | Sow outdoors (fall) | Jun 6 – Jul 22 |
| Garlic | Plant outdoors (fall) | Oct 6 – Nov 6 |
Where these dates come from
ZIP code 49740 is matched to the NOAA station Cross Village 1E, MI, 12.9 km away, at 721 ft elevation (165 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Cross Village 1E, MI (used) | 721 ft | May 15 | Oct 16 |
| Petoskey, MI | 599 ft | May 6 | Oct 20 |
| Pellston Rgnl Ap, MI | 705 ft | May 31 | Sep 18 |
| Pellston Ap #2, MI | 712 ft | May 21 | Sep 27 |
Frost dates near Harbor Springs
- Good Hart, MI 49737 · last May 15, first Oct 16
- Cross Village, MI 49723 · last May 15, first Oct 16
- Pellston, MI 49769 · last May 31, first Sep 18
- Conway, MI 49722 · last May 6, first Oct 20
- Oden, MI 49764 · last May 6, first Oct 20
- Alanson, MI 49706 · last May 31, first Sep 18
- Bay Shore, MI 49711 · last May 6, first Oct 20
- Petoskey, MI 49770 · last May 6, first Oct 20
Frequently asked questions
- When is the last frost in Harbor Springs, MI?
- For ZIP code 49740, the average last spring frost (32°F) is May 15, based on NOAA 1991-2020 climate normals for the Cross Village 1E, MI weather station. There is a 1-in-10 chance of a frost after May 30.
- When is the first frost in Harbor Springs, MI?
- The average first fall frost (32°F) is October 16. There is a 1-in-10 chance of frost by September 30, so tender plants are at risk from that point on.
- How long is the growing season in 49740?
- 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.