Frost dates for 49808Big Bay, MI
The average last spring frost in Big Bay is May 22 and the average first fall frost is October 6, giving a typical growing season of about 137 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 22
- Average first fall frost
- Oct 6
- Growing season
- 137 days
Safer after Jun 5 (1-in-10 risk)
Possible by Sep 20 (1-in-10 risk)
Last frost typically in 208 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 19 · Jun 1 · Jun 18 | Sep 6 · Sep 24 · Oct 9 | 113 days | 100% |
| Frost / freeze (32°F) | May 3 · May 22 · Jun 5 | Sep 20 · Oct 6 · Oct 22 | 137 days | 100% |
| Hard freeze (28°F) | Apr 25 · May 9 · May 27 | Oct 2 · Oct 21 · Nov 6 | 164 days | 100% |
Planting calendar for Big Bay
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 21 – Jun 27 |
| Tomatoes | Transplant outdoors | Jun 7 – Jun 16 |
| Peppers | Start seeds indoors | Apr 21 – May 22 |
| Peppers | Transplant outdoors | Jun 21 – Jul 22 |
| Eggplant | Start seeds indoors | May 8 – Jun 6 |
| Eggplant | Transplant outdoors | Jun 21 – Jul 22 |
| Cucumbers | Sow outdoors | Jun 21 – Jun 26 |
| Summer squash | Sow outdoors | Jun 7 – Jul 22 |
| Winter squash & pumpkins | Sow outdoors | Jun 21 – Jul 22 |
| Snap beans | Sow outdoors | Jun 7 – Jul 19 |
| Sweet corn | Sow outdoors | Jun 7 – Jun 16 |
| Watermelon & cantaloupe | Sow outdoors | Jun 21 – Jul 22 |
| Okra | Sow outdoors | Jun 14 – Jul 7 |
| Peas | Sow outdoors (spring) | Apr 21 – Jun 6 |
| Potatoes | Plant outdoors (spring) | Apr 21 – Jun 21 |
| Onions | Start seeds indoors (spring) | Mar 10 – Apr 6 |
| Onions | Transplant outdoors (spring) | May 8 – Jun 6 |
| Broccoli | Start seeds indoors (spring) | Apr 3 – May 7 |
| Broccoli | Transplant outdoors (spring) | May 8 – Jun 6 |
| Broccoli | Start seeds indoors (fall) | Jun 6 – Jun 16 |
| Broccoli | Transplant outdoors (fall) | Jul 6 – Jul 17 |
| Cabbage | Start seeds indoors (spring) | Mar 24 – Apr 21 |
| Cabbage | Transplant outdoors (spring) | Apr 21 – May 22 |
| Cabbage | Start seeds indoors (fall) | May 27 – Jun 26 |
| Cabbage | Transplant outdoors (fall) | Jun 26 – Jul 27 |
| Leaf lettuce | Sow outdoors (spring) | Apr 21 – Jul 7 |
| Leaf lettuce | Sow outdoors (fall) | Jun 26 – Aug 12 |
| Spinach | Sow outdoors (spring) | Apr 14 – May 28 |
| Spinach | Sow outdoors (fall) | Jul 13 – Aug 17 |
| Radishes | Sow outdoors (spring) | Apr 21 – Jun 11 |
| Radishes | Sow outdoors (fall) | Jun 26 – Aug 27 |
| Kale | Sow outdoors (spring) | May 8 – May 28 |
| Kale | Sow outdoors (fall) | Jun 19 – Jul 27 |
| Carrots | Sow outdoors (spring) | May 22 – Jul 7 |
| Carrots | Sow outdoors (fall) | May 27 – Jul 12 |
| Garlic | Plant outdoors (fall) | Sep 26 – Oct 27 |
Where these dates come from
ZIP code 49808 is matched to the NOAA station Big Bay 1Nw, MI, 2.5 km away, at 765 ft elevation (83 ft higher than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Big Bay 1Nw, MI (used) | 765 ft | May 22 | Oct 6 |
| Marquette, MI | 1,411 ft | May 22 | Sep 29 |
| Ishpeming Wwtp, MI | 1,406 ft | May 26 | Sep 25 |
| Clarksburg, MI | 1,554 ft | Jun 5 | Sep 10 |
Frost dates near Big Bay
- National Mine, MI 49865 · last May 22, first Sep 29
- Marquette, MI 49855 · last May 8, first Oct 21
- Skanee, MI 49962 · last Jun 1, first Sep 23
- Negaunee, MI 49866 · last May 22, first Sep 29
- Champion, MI 49814 · last —, first —
- Ishpeming, MI 49849 · last May 22, first Sep 29
- Michigamme, MI 49861 · last —, first —
- Palmer, MI 49871 · last May 22, first Sep 29
Frequently asked questions
- When is the last frost in Big Bay, MI?
- For ZIP code 49808, the average last spring frost (32°F) is May 22, based on NOAA 1991-2020 climate normals for the Big Bay 1Nw, MI weather station. There is a 1-in-10 chance of a frost after June 5.
- When is the first frost in Big Bay, MI?
- The average first fall frost (32°F) is October 6. 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 49808?
- In half of years, the frost-free season (between the last and first 32°F frost) is at least 137 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.