Frost dates for 49948Mass City, MI
The average last spring frost in Mass City is May 27 and the average first fall frost is October 1, giving a typical growing season of about 127 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 27
- Average first fall frost
- Oct 1
- Growing season
- 127 days
Safer after Jun 13 (1-in-10 risk)
Possible by Sep 14 (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) | May 24 · Jun 8 · Jul 1 | Aug 26 · Sep 17 · Oct 3 | 98 days | 100% |
| Frost / freeze (32°F) | May 7 · May 27 · Jun 13 | Sep 14 · Oct 1 · Oct 16 | 127 days | 100% |
| Hard freeze (28°F) | Apr 25 · May 10 · May 29 | Sep 28 · Oct 14 · Nov 1 | 157 days | 100% |
Planting calendar for Mass City
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 11 |
| 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 21 |
| Summer squash | Sow outdoors | Jun 12 – Jul 27 |
| Winter squash & pumpkins | Sow outdoors | Jun 26 – Jul 27 |
| Snap beans | Sow outdoors | Jun 12 – Jul 14 |
| Sweet corn | Sow outdoors | Jun 12 – Jun 11 |
| 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) | Jun 1 – Jun 11 |
| Broccoli | Transplant outdoors (fall) | Jul 1 – Jul 12 |
| Cabbage | Start seeds indoors (spring) | Mar 29 – Apr 26 |
| Cabbage | Transplant outdoors (spring) | Apr 26 – May 27 |
| Cabbage | Start seeds indoors (fall) | May 22 – Jun 21 |
| Cabbage | Transplant outdoors (fall) | Jun 21 – Jul 22 |
| Leaf lettuce | Sow outdoors (spring) | Apr 26 – Jul 12 |
| Leaf lettuce | Sow outdoors (fall) | Jun 21 – Aug 7 |
| Spinach | Sow outdoors (spring) | Apr 19 – Jun 2 |
| Spinach | Sow outdoors (fall) | Jul 8 – Aug 12 |
| Radishes | Sow outdoors (spring) | Apr 26 – Jun 16 |
| Radishes | Sow outdoors (fall) | Jun 21 – Aug 22 |
| Kale | Sow outdoors (spring) | May 13 – Jun 2 |
| Kale | Sow outdoors (fall) | Jun 14 – Jul 22 |
| Carrots | Sow outdoors (spring) | May 27 – Jul 12 |
| Carrots | Sow outdoors (fall) | May 22 – Jul 7 |
| Garlic | Plant outdoors (fall) | Sep 21 – Oct 22 |
Where these dates come from
ZIP code 49948 is matched to the NOAA station Ontonagon 6 Se, MI, 14.5 km away, at 790 ft elevation (227 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Ontonagon 6 Se, MI (used) | 790 ft | May 27 | Oct 1 |
| Greenland 6N, MI | 791 ft | May 23 | Oct 1 |
| Baraga 7Nw, MI | 652 ft | May 25 | Sep 23 |
| Paulding, MI | 1,367 ft | May 31 | Sep 19 |
Frost dates near Mass City
- Greenland, MI 49929 · last May 27, first Oct 1
- Rockland, MI 49960 · last May 27, first Oct 1
- Nisula, MI 49952 · last May 27, first Oct 1
- Ontonagon, MI 49953 · last May 27, first Oct 1
- Toivola, MI 49965 · last May 23, first Oct 1
- Bruce Crossing, MI 49912 · last May 26, first Sep 27
- Trout Creek, MI 49967 · last May 31, first Sep 19
- Ewen, MI 49925 · last May 26, first Sep 27
Frequently asked questions
- When is the last frost in Mass City, MI?
- For ZIP code 49948, the average last spring frost (32°F) is May 27, based on NOAA 1991-2020 climate normals for the Ontonagon 6 Se, MI weather station. There is a 1-in-10 chance of a frost after June 13.
- When is the first frost in Mass City, MI?
- The average first fall frost (32°F) is October 1. There is a 1-in-10 chance of frost by September 14, so tender plants are at risk from that point on.
- How long is the growing season in 49948?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 127 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.