Frost dates for 49891Trenary, MI
The average last spring frost in Trenary is May 27 and the average first fall frost is September 28, giving a typical growing season of about 124 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 27
- Average first fall frost
- Sep 28
- Growing season
- 124 days
Safer after Jun 12 (1-in-10 risk)
Possible by Sep 9 (1-in-10 risk)
Last frost typically in 213 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) | — | — | 92 days | 100% |
| Frost / freeze (32°F) | May 11 · May 27 · Jun 12 | Sep 9 · Sep 28 · Oct 12 | 124 days | 100% |
| Hard freeze (28°F) | Apr 28 · May 12 · May 30 | Sep 24 · Oct 11 · Oct 28 | 150 days | 100% |
Planting calendar for Trenary
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 26 – Jul 2 |
| Tomatoes | Transplant outdoors | Jun 12 – Jun 8 |
| Peppers | Start seeds indoors | Apr 26 – May 27 |
| Peppers | Transplant outdoors | Jun 26 – Jul 27 |
| Eggplant | Start seeds indoors | May 13 – Jun 11 |
| Eggplant | Transplant outdoors | Jun 26 – Jul 27 |
| Cucumbers | Sow outdoors | Jun 26 – Jun 18 |
| Summer squash | Sow outdoors | Jun 12 – Jul 27 |
| Winter squash & pumpkins | Sow outdoors | Jun 26 – Jul 27 |
| Snap beans | Sow outdoors | Jun 12 – Jul 11 |
| Sweet corn | Sow outdoors | Jun 12 – Jun 8 |
| Watermelon & cantaloupe | Sow outdoors | Jun 26 – Jul 27 |
| Okra | Sow outdoors | Jun 19 – Jul 12 |
| Peas | Sow outdoors (spring) | Apr 26 – Jun 11 |
| Potatoes | Plant outdoors (spring) | Apr 26 – Jun 26 |
| Onions | Start seeds indoors (spring) | Mar 15 – Apr 11 |
| Onions | Transplant outdoors (spring) | May 13 – Jun 11 |
| Broccoli | Start seeds indoors (spring) | Apr 8 – May 12 |
| Broccoli | Transplant outdoors (spring) | May 13 – Jun 11 |
| Broccoli | Start seeds indoors (fall) | May 29 – Jun 8 |
| Broccoli | Transplant outdoors (fall) | Jun 28 – Jul 9 |
| Cabbage | Start seeds indoors (spring) | Mar 29 – Apr 26 |
| Cabbage | Transplant outdoors (spring) | Apr 26 – May 27 |
| Cabbage | Start seeds indoors (fall) | May 19 – Jun 18 |
| Cabbage | Transplant outdoors (fall) | Jun 18 – Jul 19 |
| Leaf lettuce | Sow outdoors (spring) | Apr 26 – Jul 12 |
| Leaf lettuce | Sow outdoors (fall) | Jun 18 – Aug 4 |
| Spinach | Sow outdoors (spring) | Apr 19 – Jun 2 |
| Spinach | Sow outdoors (fall) | Jul 5 – Aug 9 |
| Radishes | Sow outdoors (spring) | Apr 26 – Jun 16 |
| Radishes | Sow outdoors (fall) | Jun 18 – Aug 19 |
| Kale | Sow outdoors (spring) | May 13 – Jun 2 |
| Kale | Sow outdoors (fall) | Jun 11 – Jul 19 |
| Carrots | Sow outdoors (spring) | May 27 – Jul 12 |
| Carrots | Sow outdoors (fall) | May 19 – Jul 4 |
| Garlic | Plant outdoors (fall) | Sep 18 – Oct 19 |
Where these dates come from
ZIP code 49891 is matched to the NOAA station Chatham 1 Se, MI, 15.7 km away, at 875 ft elevation (2 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Chatham 1 Se, MI (used) | 875 ft | May 27 | Sep 28 |
| Chatham Exp Farm 2, MI | 870 ft | May 30 | Sep 27 |
| Munising, MI | 680 ft | May 16 | Oct 14 |
| Munsing Lakeshore, MI | 612 ft | May 23 | Oct 10 |
Frost dates near Trenary
- Chatham, MI 49816 · last May 30, first Sep 27
- Eben Junction, MI 49825 · last May 30, first Sep 27
- Rumely, MI 49826 · last May 30, first Sep 27
- Rock, MI 49880 · last May 19, first Oct 1
- Perkins, MI 49872 · last May 19, first Oct 1
- Deerton, MI 49822 · last May 30, first Sep 27
- Au Train, MI 49806 · last May 16, first Oct 14
- Skandia, MI 49885 · last May 13, first Oct 2
Frequently asked questions
- When is the last frost in Trenary, MI?
- For ZIP code 49891, the average last spring frost (32°F) is May 27, based on NOAA 1991-2020 climate normals for the Chatham 1 Se, MI weather station. There is a 1-in-10 chance of a frost after June 12.
- When is the first frost in Trenary, MI?
- The average first fall frost (32°F) is September 28. There is a 1-in-10 chance of frost by September 9, so tender plants are at risk from that point on.
- How long is the growing season in 49891?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 124 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.