Frost dates for 48467Port Austin, MI
The average last spring frost in Port Austin is May 8 and the average first fall frost is October 17, giving a typical growing season of about 162 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 8
- Average first fall frost
- Oct 17
- Growing season
- 162 days
Safer after May 22 (1-in-10 risk)
Possible by Sep 28 (1-in-10 risk)
Last frost typically in 187 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 4 · May 20 · Jun 2 | Sep 14 · Oct 1 · Oct 17 | 134 days | 100% |
| Frost / freeze (32°F) | Apr 24 · May 8 · May 22 | Sep 28 · Oct 17 · Nov 1 | 162 days | 100% |
| Hard freeze (28°F) | Apr 10 · Apr 27 · May 11 | Oct 15 · Nov 1 · Nov 15 | 187 days | 100% |
Planting calendar for Port Austin
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 7 – Jun 13 |
| Tomatoes | Transplant outdoors | May 24 – Jun 27 |
| Peppers | Start seeds indoors | Apr 7 – May 8 |
| Peppers | Transplant outdoors | Jun 7 – Jul 8 |
| Eggplant | Start seeds indoors | Apr 24 – May 23 |
| Eggplant | Transplant outdoors | Jun 7 – Jul 8 |
| Cucumbers | Sow outdoors | Jun 7 – Jul 7 |
| Summer squash | Sow outdoors | May 24 – Jul 8 |
| Winter squash & pumpkins | Sow outdoors | Jun 7 – Jul 8 |
| Snap beans | Sow outdoors | May 24 – Jul 30 |
| Sweet corn | Sow outdoors | May 24 – Jun 27 |
| Watermelon & cantaloupe | Sow outdoors | Jun 7 – Jul 8 |
| Okra | Sow outdoors | May 31 – Jun 23 |
| Peas | Sow outdoors (spring) | Apr 7 – May 23 |
| Potatoes | Plant outdoors (spring) | Apr 7 – Jun 7 |
| Onions | Start seeds indoors (spring) | Feb 24 – Mar 23 |
| Onions | Transplant outdoors (spring) | Apr 24 – May 23 |
| Broccoli | Start seeds indoors (spring) | Mar 20 – Apr 23 |
| Broccoli | Transplant outdoors (spring) | Apr 24 – May 23 |
| Broccoli | Start seeds indoors (fall) | Jun 17 – Jun 27 |
| Broccoli | Transplant outdoors (fall) | Jul 17 – Jul 28 |
| Cabbage | Start seeds indoors (spring) | Mar 10 – Apr 7 |
| Cabbage | Transplant outdoors (spring) | Apr 7 – May 8 |
| Cabbage | Start seeds indoors (fall) | Jun 7 – Jul 7 |
| Cabbage | Transplant outdoors (fall) | Jul 7 – Aug 7 |
| Leaf lettuce | Sow outdoors (spring) | Apr 7 – Jun 23 |
| Leaf lettuce | Sow outdoors (fall) | Jul 7 – Aug 23 |
| Spinach | Sow outdoors (spring) | Mar 31 – May 14 |
| Spinach | Sow outdoors (fall) | Jul 24 – Aug 28 |
| Radishes | Sow outdoors (spring) | Apr 7 – May 28 |
| Radishes | Sow outdoors (fall) | Jul 7 – Sep 7 |
| Kale | Sow outdoors (spring) | Apr 24 – May 14 |
| Kale | Sow outdoors (fall) | Jun 30 – Aug 7 |
| Carrots | Sow outdoors (spring) | May 8 – Jun 23 |
| Carrots | Sow outdoors (fall) | Jun 7 – Jul 23 |
| Garlic | Plant outdoors (fall) | Oct 7 – Nov 7 |
Where these dates come from
ZIP code 48467 is matched to the NOAA station Filion 5Nnw, MI, 13.6 km away, at 635 ft elevation (5 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Filion 5Nnw, MI (used) | 635 ft | May 8 | Oct 17 |
| Port Austin Wwtp, MI | 605 ft | May 4 | Oct 26 |
| Port Hope, MI | 590 ft | Apr 28 | Nov 3 |
| Bad Axe, MI | 715 ft | May 5 | Oct 19 |
Frost dates near Port Austin
- Kinde, MI 48445 · last May 8, first Oct 17
- Filion, MI 48432 · last May 5, first Oct 19
- Port Hope, MI 48468 · last May 5, first Oct 24
- Caseville, MI 48725 · last May 8, first Oct 17
- Bad Axe, MI 48413 · last May 5, first Oct 19
- Elkton, MI 48731 · last May 8, first Oct 17
- Pigeon, MI 48755 · last May 8, first Oct 17
- Harbor Beach, MI 48441 · last May 2, first Oct 24
Frequently asked questions
- When is the last frost in Port Austin, MI?
- For ZIP code 48467, the average last spring frost (32°F) is May 8, based on NOAA 1991-2020 climate normals for the Filion 5Nnw, MI weather station. There is a 1-in-10 chance of a frost after May 22.
- When is the first frost in Port Austin, MI?
- The average first fall frost (32°F) is October 17. There is a 1-in-10 chance of frost by September 28, so tender plants are at risk from that point on.
- How long is the growing season in 48467?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 162 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.