Frost dates for 49878Rapid River, MI
The average last spring frost in Rapid River is May 18 and the average first fall frost is October 4, giving a typical growing season of about 137 days. Dates are based on NOAA 1991-2020 climate normals.
- Average last spring frost
- May 18
- Average first fall frost
- Oct 4
- Growing season
- 137 days
Safer after Jun 2 (1-in-10 risk)
Possible by Sep 18 (1-in-10 risk)
Last frost typically in 204 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 17 · May 31 · Jun 12 | Sep 5 · Sep 22 · Oct 5 | 114 days | 100% |
| Frost / freeze (32°F) | May 3 · May 18 · Jun 2 | Sep 18 · Oct 4 · Oct 18 | 137 days | 100% |
| Hard freeze (28°F) | Apr 23 · May 5 · May 21 | Oct 1 · Oct 17 · Nov 2 | 162 days | 100% |
Planting calendar for Rapid River
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 17 – Jun 23 |
| Tomatoes | Transplant outdoors | Jun 3 – Jun 14 |
| Peppers | Start seeds indoors | Apr 17 – May 18 |
| Peppers | Transplant outdoors | Jun 17 – Jul 18 |
| Eggplant | Start seeds indoors | May 4 – Jun 2 |
| Eggplant | Transplant outdoors | Jun 17 – Jul 18 |
| Cucumbers | Sow outdoors | Jun 17 – Jun 24 |
| Summer squash | Sow outdoors | Jun 3 – Jul 18 |
| Winter squash & pumpkins | Sow outdoors | Jun 17 – Jul 18 |
| Snap beans | Sow outdoors | Jun 3 – Jul 17 |
| Sweet corn | Sow outdoors | Jun 3 – Jun 14 |
| Watermelon & cantaloupe | Sow outdoors | Jun 17 – Jul 18 |
| Okra | Sow outdoors | Jun 10 – Jul 3 |
| Peas | Sow outdoors (spring) | Apr 17 – Jun 2 |
| Potatoes | Plant outdoors (spring) | Apr 17 – Jun 17 |
| Onions | Start seeds indoors (spring) | Mar 6 – Apr 2 |
| Onions | Transplant outdoors (spring) | May 4 – Jun 2 |
| Broccoli | Start seeds indoors (spring) | Mar 30 – May 3 |
| Broccoli | Transplant outdoors (spring) | May 4 – Jun 2 |
| Broccoli | Start seeds indoors (fall) | Jun 4 – Jun 14 |
| Broccoli | Transplant outdoors (fall) | Jul 4 – Jul 15 |
| Cabbage | Start seeds indoors (spring) | Mar 20 – Apr 17 |
| Cabbage | Transplant outdoors (spring) | Apr 17 – May 18 |
| Cabbage | Start seeds indoors (fall) | May 25 – Jun 24 |
| Cabbage | Transplant outdoors (fall) | Jun 24 – Jul 25 |
| Leaf lettuce | Sow outdoors (spring) | Apr 17 – Jul 3 |
| Leaf lettuce | Sow outdoors (fall) | Jun 24 – Aug 10 |
| Spinach | Sow outdoors (spring) | Apr 10 – May 24 |
| Spinach | Sow outdoors (fall) | Jul 11 – Aug 15 |
| Radishes | Sow outdoors (spring) | Apr 17 – Jun 7 |
| Radishes | Sow outdoors (fall) | Jun 24 – Aug 25 |
| Kale | Sow outdoors (spring) | May 4 – May 24 |
| Kale | Sow outdoors (fall) | Jun 17 – Jul 25 |
| Carrots | Sow outdoors (spring) | May 18 – Jul 3 |
| Carrots | Sow outdoors (fall) | May 25 – Jul 10 |
| Garlic | Plant outdoors (fall) | Sep 24 – Oct 25 |
Where these dates come from
ZIP code 49878 is matched to the NOAA station Rapid Rvr 4Sse, MI, 6.6 km away, at 598 ft elevation (107 ft lower than the ZIP code's center). Nearby stations for comparison:
| Station | Elevation | Avg last frost | Avg first frost |
|---|---|---|---|
| Rapid Rvr 4Sse, MI (used) | 598 ft | May 18 | Oct 4 |
| Cornell 5Se, MI | 794 ft | May 19 | Oct 1 |
| Garden Corners, MI | 587 ft | May 16 | Sep 24 |
| Escanaba, MI | 590 ft | May 13 | Oct 7 |
Frost dates near Rapid River
- Perkins, MI 49872 · last May 19, first Oct 1
- Gladstone, MI 49837 · last May 19, first Oct 1
- Nahma, MI 49864 · last May 16, first Sep 24
- Wells, MI 49894 · last May 19, first Oct 1
- Escanaba, MI 49829 · last May 19, first Oct 1
- Rock, MI 49880 · last May 19, first Oct 1
- Cornell, MI 49818 · last May 19, first Oct 1
- Cooks, MI 49817 · last May 16, first Sep 24
Frequently asked questions
- When is the last frost in Rapid River, MI?
- For ZIP code 49878, the average last spring frost (32°F) is May 18, based on NOAA 1991-2020 climate normals for the Rapid Rvr 4Sse, MI weather station. There is a 1-in-10 chance of a frost after June 2.
- When is the first frost in Rapid River, MI?
- The average first fall frost (32°F) is October 4. There is a 1-in-10 chance of frost by September 18, so tender plants are at risk from that point on.
- How long is the growing season in 49878?
- 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.