Mackinac Island, MI frost dates
Last spring frostMay 16median date
First fall frostOct 13median date
Growing season150 daysfrost-free
Hardiness zone5bZone 5b
How Mackinac Island compares
- In 8 years out of 10, the last spring frost in Mackinac Island falls between April 30 and May 29, a 29-day window. The first fall frost falls between September 30 and October 30.
- The median last frost is 11 days later than the Michigan median of May 5.
- Its 150-day growing season is longer than 33% of the 878 Michigan places with a regular frost season (state median 162 days).
- The last frost is 15 days later than the zone 5b median of May 1. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 5b chart.
- The weather station records an average of 165 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 30 |
| 50% (median) | May 16 |
| 10% (safe for tender plants) | May 29 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 30 |
| 50% (median) | October 13 |
| 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 Mackinac Island, MI
Mackinac Island, MI frost dates — last frost May 16, first frost Oct 13, zone 5b. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Feb 21 to Mar 7Transplant outside: Apr 18 to May 2
Start indoors: Mar 7 to Mar 21Transplant outside: May 30 to Jun 13
Start indoors: Mar 7 to Mar 21Transplant outside: May 30 to Jun 13
Start indoors: Mar 21 to Apr 4Transplant outside: May 23 to Jun 6
Start indoors: Mar 21 to Apr 4Transplant outside: Apr 25 to May 9Sow outdoors: Apr 18 to May 23Plant for fall: Aug 18 to Sep 15
Start indoors: Mar 21 to Apr 4Transplant outside: Apr 18 to May 2Sow outdoors: Apr 18 to May 2Plant for fall: Aug 4 to Aug 25
Start indoors: Mar 21 to Apr 4Transplant outside: May 2 to May 16Plant for fall: Jul 7 to Jul 28
Start indoors: Mar 21 to Apr 4Transplant outside: Apr 25 to May 9Plant for fall: Jul 7 to Jul 28
Start indoors: Mar 21 to Apr 4Transplant outside: May 2 to May 16Plant for fall: Jul 7 to Jul 28
Start indoors: Apr 4 to Apr 18Transplant outside: Jun 6 to Jun 20Sow outdoors: Jun 6 to Jun 20
Start indoors: Apr 4 to Apr 18Transplant outside: May 23 to Jun 6
Sow outdoors: Apr 4 to Apr 25Plant for fall: Jul 21 to Aug 11
Sow outdoors: Apr 4 to Apr 25Plant for fall: Aug 18 to Sep 8
Sow outdoors: Apr 11 to May 23Plant for fall: Sep 1 to Sep 22
Start indoors: Apr 18 to Apr 25Transplant outside: May 30 to Jun 6Sow outdoors: May 23 to Jun 6Plant for fall: Jul 28 to Aug 11
Start indoors: Apr 18 to Apr 25Sow outdoors: May 23 to Jun 6Plant for fall: Aug 4 to Aug 18
Start indoors: Apr 18 to Apr 25Sow outdoors: May 23 to Jun 6
Start indoors: Apr 18 to Apr 25Transplant outside: May 30 to Jun 13
Sow outdoors: Apr 25 to May 23Plant for fall: Jul 21 to Aug 4
Sow outdoors: Apr 25 to May 23Plant for fall: Aug 4 to Aug 18
Sow outdoors: Apr 25 to May 16
Sow outdoors: May 2 to May 30Plant for fall: Aug 4 to Aug 18
Sow outdoors: May 2 to May 23Plant for fall: Aug 18 to Sep 8
Sow outdoors: May 23 to Jun 13Plant for fall: Jul 28 to Aug 11
Sow outdoors: May 23 to Jun 6
Transplant outside: May 30 to Jun 20
Plant for fall: Sep 29 to Nov 3
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Mackinac Island, MI
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 21 – Mar 7 | Apr 18 – May 2 | — | — |
| Peppers | Mar 7 – Mar 21 | May 30 – Jun 13 | — | — |
| Eggplant | Mar 7 – Mar 21 | May 30 – Jun 13 | — | — |
| Tomatoes | Mar 21 – Apr 4 | May 23 – Jun 6 | — | — |
| Lettuce | Mar 21 – Apr 4 | Apr 25 – May 9 | Apr 18 – May 23 | Aug 18 – Sep 15 |
| Kale | Mar 21 – Apr 4 | Apr 18 – May 2 | Apr 18 – May 2 | Aug 4 – Aug 25 |
| Broccoli | Mar 21 – Apr 4 | May 2 – May 16 | — | Jul 7 – Jul 28 |
| Cabbage | Mar 21 – Apr 4 | Apr 25 – May 9 | — | Jul 7 – Jul 28 |
| Cauliflower | Mar 21 – Apr 4 | May 2 – May 16 | — | Jul 7 – Jul 28 |
| Okra | Apr 4 – Apr 18 | Jun 6 – Jun 20 | Jun 6 – Jun 20 | — |
| Basil | Apr 4 – Apr 18 | May 23 – Jun 6 | — | — |
| Peas | — | — | Apr 4 – Apr 25 | Jul 21 – Aug 11 |
| Spinach | — | — | Apr 4 – Apr 25 | Aug 18 – Sep 8 |
| Radishes | — | — | Apr 11 – May 23 | Sep 1 – Sep 22 |
| Cucumbers | Apr 18 – Apr 25 | May 30 – Jun 6 | May 23 – Jun 6 | Jul 28 – Aug 11 |
| Zucchini & Summer Squash | Apr 18 – Apr 25 | — | May 23 – Jun 6 | Aug 4 – Aug 18 |
| Winter Squash & Pumpkins | Apr 18 – Apr 25 | — | May 23 – Jun 6 | — |
| Melons & Watermelon | Apr 18 – Apr 25 | May 30 – Jun 13 | — | — |
| Carrots | — | — | Apr 25 – May 23 | Jul 21 – Aug 4 |
| Beets | — | — | Apr 25 – May 23 | Aug 4 – Aug 18 |
| Potatoes | — | — | Apr 25 – May 16 | — |
| Swiss Chard | — | — | May 2 – May 30 | Aug 4 – Aug 18 |
| Cilantro | — | — | May 2 – May 23 | Aug 18 – Sep 8 |
| Green Beans | — | — | May 23 – Jun 13 | Jul 28 – Aug 11 |
| Sweet Corn | — | — | May 23 – Jun 6 | — |
| Sweet Potatoes | — | May 30 – Jun 20 | — | — |
| Garlic | — | — | — | Sep 29 – Nov 3 |
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 St Ignace, MI weather station, 7 km away (elevation 663 ft (202 m)).
Frost dates near Mackinac Island
- Mackinaw City May 7 · Oct 23
- Saint Ignace May 23 · Sep 30
- Carp Lake May 7 · Oct 23
- Pointe Aux Pins May 11 · Oct 11
- Hessel Jun 1 · Sep 21
- Cedarville May 31 · Sep 25
- Levering May 21 · Sep 27
- Cheboygan May 11 · Oct 11
- Mullett Lake May 11 · Oct 11
- Moran May 23 · Sep 30
Frequently asked questions
When is the last frost in Mackinac Island, MI?
The median last spring frost in Mackinac Island, MI is May 16. There is still about a 10% chance of frost after May 29, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Mackinac Island, MI?
The median first fall frost is October 13, with about a 10% chance of frost before September 30.
How long is the growing season in Mackinac Island, MI?
About 150 days between the median last spring frost and first fall frost.
What planting zone is Mackinac Island, MI?
Mackinac Island, MI is in USDA hardiness zone 5b.