Black River, MI frost dates
Last spring frostMay 8median date
First fall frostOct 16median date
Growing season161 daysfrost-free
Hardiness zone6aZone 6a
How Black River compares
- In 8 years out of 10, the last spring frost in Black River falls between April 26 and May 24, a 28-day window. The first fall frost falls between October 2 and October 30.
- The median last frost is 3 days later than the Michigan median of May 5.
- Its 161-day growing season is longer than 47% of the 878 Michigan places with a regular frost season (state median 162 days).
- The last frost is 9 days later than the zone 6a median of Apr 29. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 6a chart.
- The weather station records an average of 150 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 26 |
| 50% (median) | May 8 |
| 10% (safe for tender plants) | May 24 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | October 2 |
| 50% (median) | October 16 |
| 90% (late) | October 30 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Black River, MI
Black River, MI frost dates — last frost May 8, first frost Oct 16, zone 6a. whenisthelastfrost.com
Crop
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Start indoors: Feb 13 to Feb 27Transplant outside: Apr 10 to Apr 24
Start indoors: Feb 27 to Mar 13Transplant outside: May 22 to Jun 5
Start indoors: Feb 27 to Mar 13Transplant outside: May 22 to Jun 5
Start indoors: Mar 13 to Mar 27Transplant outside: May 15 to May 29
Start indoors: Mar 13 to Mar 27Transplant outside: Apr 17 to May 1Sow outdoors: Apr 10 to May 15Plant for fall: Aug 21 to Sep 18
Start indoors: Mar 13 to Mar 27Transplant outside: Apr 10 to Apr 24Sow outdoors: Apr 10 to Apr 24Plant for fall: Aug 7 to Aug 28
Start indoors: Mar 13 to Mar 27Transplant outside: Apr 24 to May 8Plant for fall: Jul 10 to Jul 31
Start indoors: Mar 13 to Mar 27Transplant outside: Apr 17 to May 1Plant for fall: Jul 10 to Jul 31
Start indoors: Mar 13 to Mar 27Transplant outside: Apr 24 to May 8Plant for fall: Jul 10 to Jul 31
Start indoors: Mar 27 to Apr 10Transplant outside: May 29 to Jun 12Sow outdoors: May 29 to Jun 12
Start indoors: Mar 27 to Apr 10Transplant outside: May 15 to May 29
Sow outdoors: Mar 27 to Apr 17Plant for fall: Jul 24 to Aug 14
Sow outdoors: Mar 27 to Apr 17Plant for fall: Aug 21 to Sep 11
Sow outdoors: Apr 3 to May 15Plant for fall: Sep 4 to Sep 25
Start indoors: Apr 10 to Apr 17Transplant outside: May 22 to May 29Sow outdoors: May 15 to May 29Plant for fall: Jul 31 to Aug 14
Start indoors: Apr 10 to Apr 17Sow outdoors: May 15 to May 29Plant for fall: Aug 7 to Aug 21
Start indoors: Apr 10 to Apr 17Sow outdoors: May 15 to May 29
Start indoors: Apr 10 to Apr 17Transplant outside: May 22 to Jun 5
Sow outdoors: Apr 17 to May 15Plant for fall: Jul 24 to Aug 7
Sow outdoors: Apr 17 to May 15Plant for fall: Aug 7 to Aug 21
Sow outdoors: Apr 17 to May 8
Sow outdoors: Apr 24 to May 22Plant for fall: Aug 7 to Aug 21
Sow outdoors: Apr 24 to May 15Plant for fall: Aug 21 to Sep 11
Sow outdoors: May 15 to Jun 5Plant for fall: Jul 31 to Aug 14
Sow outdoors: May 15 to May 29
Transplant outside: May 22 to Jun 12
Plant for fall: Oct 2 to Nov 6
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Black River, MI
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 13 – Feb 27 | Apr 10 – Apr 24 | — | — |
| Peppers | Feb 27 – Mar 13 | May 22 – Jun 5 | — | — |
| Eggplant | Feb 27 – Mar 13 | May 22 – Jun 5 | — | — |
| Tomatoes | Mar 13 – Mar 27 | May 15 – May 29 | — | — |
| Lettuce | Mar 13 – Mar 27 | Apr 17 – May 1 | Apr 10 – May 15 | Aug 21 – Sep 18 |
| Kale | Mar 13 – Mar 27 | Apr 10 – Apr 24 | Apr 10 – Apr 24 | Aug 7 – Aug 28 |
| Broccoli | Mar 13 – Mar 27 | Apr 24 – May 8 | — | Jul 10 – Jul 31 |
| Cabbage | Mar 13 – Mar 27 | Apr 17 – May 1 | — | Jul 10 – Jul 31 |
| Cauliflower | Mar 13 – Mar 27 | Apr 24 – May 8 | — | Jul 10 – Jul 31 |
| Okra | Mar 27 – Apr 10 | May 29 – Jun 12 | May 29 – Jun 12 | — |
| Basil | Mar 27 – Apr 10 | May 15 – May 29 | — | — |
| Peas | — | — | Mar 27 – Apr 17 | Jul 24 – Aug 14 |
| Spinach | — | — | Mar 27 – Apr 17 | Aug 21 – Sep 11 |
| Radishes | — | — | Apr 3 – May 15 | Sep 4 – Sep 25 |
| Cucumbers | Apr 10 – Apr 17 | May 22 – May 29 | May 15 – May 29 | Jul 31 – Aug 14 |
| Zucchini & Summer Squash | Apr 10 – Apr 17 | — | May 15 – May 29 | Aug 7 – Aug 21 |
| Winter Squash & Pumpkins | Apr 10 – Apr 17 | — | May 15 – May 29 | — |
| Melons & Watermelon | Apr 10 – Apr 17 | May 22 – Jun 5 | — | — |
| Carrots | — | — | Apr 17 – May 15 | Jul 24 – Aug 7 |
| Beets | — | — | Apr 17 – May 15 | Aug 7 – Aug 21 |
| Potatoes | — | — | Apr 17 – May 8 | — |
| Swiss Chard | — | — | Apr 24 – May 22 | Aug 7 – Aug 21 |
| Cilantro | — | — | Apr 24 – May 15 | Aug 21 – Sep 11 |
| Green Beans | — | — | May 15 – Jun 5 | Jul 31 – Aug 14 |
| Sweet Corn | — | — | May 15 – May 29 | — |
| Sweet Potatoes | — | May 22 – Jun 12 | — | — |
| Garlic | — | — | — | Oct 2 – Nov 6 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Harrisville 2nne, MI weather station, 15 km away (elevation 584 ft (178 m)).
Frost dates near Black River
- Lincoln May 8 · Oct 16
- Spruce May 8 · Oct 16
- Ossineke May 5 · Oct 17
- Harrisville May 8 · Oct 16
- Hubbard Lake May 17 · Oct 1
- Barton City May 19 · Sep 29
- Mikado May 8 · Oct 16
- Greenbush May 8 · Oct 16
- Alpena May 5 · Oct 17
- Herron May 17 · Oct 1
Frequently asked questions
When is the last frost in Black River, MI?
The median last spring frost in Black River, MI is May 8. There is still about a 10% chance of frost after May 24, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Black River, MI?
The median first fall frost is October 16, with about a 10% chance of frost before October 2.
How long is the growing season in Black River, MI?
About 161 days between the median last spring frost and first fall frost.
What planting zone is Black River, MI?
Black River, MI is in USDA hardiness zone 6a.