Corunna, MI frost dates
Last spring frostMay 5median date
First fall frostOct 14median date
Growing season162 daysfrost-free
Hardiness zone6aZone 6a
How Corunna compares
- In 8 years out of 10, the last spring frost in Corunna falls between April 20 and May 20, a 30-day window. The first fall frost falls between September 29 and October 29.
- The median last frost is the same as the Michigan median of May 5.
- Its 162-day growing season is longer than 49% of the 878 Michigan places with a regular frost season (state median 162 days).
- The last frost is 6 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 155 nights a year at or below 32°F.
- Compared with Flint, MI, 25 km away, the last frost here is 2 days later than there and the growing season is 1 day shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 20 |
| 50% (median) | May 5 |
| 10% (safe for tender plants) | May 20 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 29 |
| 50% (median) | October 14 |
| 90% (late) | October 29 |
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 Corunna, MI
Corunna, MI frost dates — last frost May 5, first frost Oct 14, zone 6a. whenisthelastfrost.com
Crop
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Start indoors: Feb 10 to Feb 24Transplant outside: Apr 7 to Apr 21
Start indoors: Feb 24 to Mar 10Transplant outside: May 19 to Jun 2
Start indoors: Feb 24 to Mar 10Transplant outside: May 19 to Jun 2
Start indoors: Mar 10 to Mar 24Transplant outside: May 12 to May 26
Start indoors: Mar 10 to Mar 24Transplant outside: Apr 14 to Apr 28Sow outdoors: Apr 7 to May 12Plant for fall: Aug 19 to Sep 16
Start indoors: Mar 10 to Mar 24Transplant outside: Apr 7 to Apr 21Sow outdoors: Apr 7 to Apr 21Plant for fall: Aug 5 to Aug 26
Start indoors: Mar 10 to Mar 24Transplant outside: Apr 21 to May 5Plant for fall: Jul 8 to Jul 29
Start indoors: Mar 10 to Mar 24Transplant outside: Apr 14 to Apr 28Plant for fall: Jul 8 to Jul 29
Start indoors: Mar 10 to Mar 24Transplant outside: Apr 21 to May 5Plant for fall: Jul 8 to Jul 29
Start indoors: Mar 24 to Apr 7Transplant outside: May 26 to Jun 9Sow outdoors: May 26 to Jun 9
Start indoors: Mar 24 to Apr 7Transplant outside: May 12 to May 26
Sow outdoors: Mar 24 to Apr 14Plant for fall: Jul 22 to Aug 12
Sow outdoors: Mar 24 to Apr 14Plant for fall: Aug 19 to Sep 9
Sow outdoors: Mar 31 to May 12Plant for fall: Sep 2 to Sep 23
Start indoors: Apr 7 to Apr 14Transplant outside: May 19 to May 26Sow outdoors: May 12 to May 26Plant for fall: Jul 29 to Aug 12
Start indoors: Apr 7 to Apr 14Sow outdoors: May 12 to May 26Plant for fall: Aug 5 to Aug 19
Start indoors: Apr 7 to Apr 14Sow outdoors: May 12 to May 26
Start indoors: Apr 7 to Apr 14Transplant outside: May 19 to Jun 2
Sow outdoors: Apr 14 to May 12Plant for fall: Jul 22 to Aug 5
Sow outdoors: Apr 14 to May 12Plant for fall: Aug 5 to Aug 19
Sow outdoors: Apr 14 to May 5
Sow outdoors: Apr 21 to May 19Plant for fall: Aug 5 to Aug 19
Sow outdoors: Apr 21 to May 12Plant for fall: Aug 19 to Sep 9
Sow outdoors: May 12 to Jun 2Plant for fall: Jul 29 to Aug 12
Sow outdoors: May 12 to May 26
Transplant outside: May 19 to Jun 9
Plant for fall: Sep 30 to Nov 4
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Corunna, MI
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 10 – Feb 24 | Apr 7 – Apr 21 | — | — |
| Peppers | Feb 24 – Mar 10 | May 19 – Jun 2 | — | — |
| Eggplant | Feb 24 – Mar 10 | May 19 – Jun 2 | — | — |
| Tomatoes | Mar 10 – Mar 24 | May 12 – May 26 | — | — |
| Lettuce | Mar 10 – Mar 24 | Apr 14 – Apr 28 | Apr 7 – May 12 | Aug 19 – Sep 16 |
| Kale | Mar 10 – Mar 24 | Apr 7 – Apr 21 | Apr 7 – Apr 21 | Aug 5 – Aug 26 |
| Broccoli | Mar 10 – Mar 24 | Apr 21 – May 5 | — | Jul 8 – Jul 29 |
| Cabbage | Mar 10 – Mar 24 | Apr 14 – Apr 28 | — | Jul 8 – Jul 29 |
| Cauliflower | Mar 10 – Mar 24 | Apr 21 – May 5 | — | Jul 8 – Jul 29 |
| Okra | Mar 24 – Apr 7 | May 26 – Jun 9 | May 26 – Jun 9 | — |
| Basil | Mar 24 – Apr 7 | May 12 – May 26 | — | — |
| Peas | — | — | Mar 24 – Apr 14 | Jul 22 – Aug 12 |
| Spinach | — | — | Mar 24 – Apr 14 | Aug 19 – Sep 9 |
| Radishes | — | — | Mar 31 – May 12 | Sep 2 – Sep 23 |
| Cucumbers | Apr 7 – Apr 14 | May 19 – May 26 | May 12 – May 26 | Jul 29 – Aug 12 |
| Zucchini & Summer Squash | Apr 7 – Apr 14 | — | May 12 – May 26 | Aug 5 – Aug 19 |
| Winter Squash & Pumpkins | Apr 7 – Apr 14 | — | May 12 – May 26 | — |
| Melons & Watermelon | Apr 7 – Apr 14 | May 19 – Jun 2 | — | — |
| Carrots | — | — | Apr 14 – May 12 | Jul 22 – Aug 5 |
| Beets | — | — | Apr 14 – May 12 | Aug 5 – Aug 19 |
| Potatoes | — | — | Apr 14 – May 5 | — |
| Swiss Chard | — | — | Apr 21 – May 19 | Aug 5 – Aug 19 |
| Cilantro | — | — | Apr 21 – May 12 | Aug 19 – Sep 9 |
| Green Beans | — | — | May 12 – Jun 2 | Jul 29 – Aug 12 |
| Sweet Corn | — | — | May 12 – May 26 | — |
| Sweet Potatoes | — | May 19 – Jun 9 | — | — |
| Garlic | — | — | — | Sep 30 – Nov 4 |
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 Corunna 2 Ne, MI weather station, 6 km away (elevation 761 ft (232 m)).
Frost dates near Corunna
- Vernon May 3 · Oct 11
- Lennon May 3 · Oct 11
- New Lothrop May 5 · Oct 14
- Owosso May 1 · Oct 15
- Durand May 3 · Oct 11
- Flushing May 3 · Oct 13
- Chesaning May 1 · Oct 15
- Henderson May 1 · Oct 15
- Montrose May 3 · Oct 13
- Oakley May 1 · Oct 15
Frequently asked questions
When is the last frost in Corunna, MI?
The median last spring frost in Corunna, MI is May 5. There is still about a 10% chance of frost after May 20, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Corunna, MI?
The median first fall frost is October 14, with about a 10% chance of frost before September 29.
How long is the growing season in Corunna, MI?
About 162 days between the median last spring frost and first fall frost.
What planting zone is Corunna, MI?
Corunna, MI is in USDA hardiness zone 6a.