Michigan weather and outdoor projects
Michigan’s weather is shaped by the Great Lakes. Detroit in the southeast has the longest warm season, Grand Rapids in the west gets more lake-effect clouds and snow, and the Upper Peninsula around Sault Ste. Marie has a short summer and long winter. The lakes keep spring cool near the shore and keep fall mild a little longer.
June through mid-September is the main window for staining and painting in most of the state. Cloudy, damp stretches are common in fall near the lakes, which slows drying. Hard freezes and freeze-thaw cycles make fall concrete and driveway work time-sensitive.
Frost dates in Michigan
In Detroit, the median last spring freeze (32°F) is around April 20 and the median first fall freeze is around October 27, a frost-free season of about 188 days.
In Grand Rapids, the median last spring freeze (32°F) is around April 29 and the median first fall freeze is around October 20, a frost-free season of about 174 days.
In Sault Ste. Marie, the median last spring freeze (32°F) is around May 9 and the median first fall freeze is around October 11, a frost-free season of about 151 days.
How Michigan compares with other states
Detroit is tied for the 7th-longest deck staining season of the 50 state main stations (5 good months). Detroit is tied for the 8th-fewest days at 90°F or hotter of the 50 state main stations (13 a year). Detroit has the 15th-shortest frost-free season of the 50 state main stations (188 days).
| Measure (Detroit) | Value | Rank, highest first |
|---|---|---|
| Deck staining season | 5 good months | 7th of 50 |
| Frost-free season | 188 days | 36th of 50 |
| Freezing nights | 120 a year | 16th of 50 |
| Rainy days | 74 a year with 0.1 in or more | 24th of 50 |
| Days at 90°F or hotter | 13 a year | 42nd of 50 |
| Summer afternoons | 50% humidity at 3 PM, June–August | 20th of 47 |
Best time to stain a deck in Michigan
In Detroit, the most reliable months are May–September. April and October can also work on the right days (average highs Apr 59°F, Oct 62°F). November–March is too cold, with average highs around 40°F. April is cool, with highs around 59°F, so choose the warmest afternoons. In October, nights average about 44°F, so finish early on mild days and check the overnight low.
In Grand Rapids, the most reliable months are May–September. October can also work on the right days (average highs Oct 61°F). November–March is too cold, with average highs around 39°F. In April, nights average about 37°F, too cold for the coating to dry and cure overnight. October is cool, with highs around 61°F, so choose the warmest afternoons.
In Sault Ste. Marie, the most reliable months are June–August. May and September can also work on the right days (average highs May 63°F, Sep 68°F). October–April is too cold, with average highs around 37°F. In May, nights average about 41°F, so finish early on mild days and check the overnight low. September averages about 8 wet days a month, so wait for a clear stretch.
Best time to paint outside in Michigan
In Detroit, the most reliable months are May–September. April and October can also work on the right days (average highs Apr 59°F, Oct 62°F). November–March is too cold, with average highs around 40°F. In April and October, nights average about 42°F, so finish early on mild days and check the overnight low.
In Grand Rapids, the most reliable months are May–September. April and October can also work on the right days (average highs Apr 58°F, Oct 61°F). November–March is too cold, with average highs around 39°F. April is cool, with highs around 58°F, so choose the warmest afternoons. In October, nights average about 42°F, so finish early on mild days and check the overnight low.
In Sault Ste. Marie, the most reliable months are June–August. May and September–October can also work on the right days (average highs May 63°F, Sep 68°F, Oct 54°F). November–April is too cold, with average highs around 34°F. In May, nights average about 41°F, so finish early on mild days and check the overnight low. September averages about 8 wet days a month, so wait for a clear stretch. October is cool, with highs around 54°F, so choose the warmest afternoons.
Best time to pour concrete in Michigan
In Detroit, the most reliable months are May–September. April and October can also work on the right days (average highs Apr 59°F, Oct 62°F). November–March averages about 22 nights a month at or below 32°F, so fresh concrete needs blankets or heated enclosures. April and October bring about 4 freezing nights a month, so pick a mild spell and keep curing blankets on hand.
In Grand Rapids, the most reliable months are May–September. October can also work on the right days (average highs Oct 61°F). November–April averages about 21 nights a month at or below 32°F, so fresh concrete needs blankets or heated enclosures. October brings about 4 freezing nights a month, so pick a mild spell and keep curing blankets on hand.
In Sault Ste. Marie, the most reliable months are June–September. May and October can also work on the right days (average highs May 63°F, Oct 54°F). November–April averages about 25 nights a month at or below 32°F, so fresh concrete needs blankets or heated enclosures. May and October bring about 6 freezing nights a month, so pick a mild spell and keep curing blankets on hand.
Best time to seal a driveway in Michigan
In Detroit, the most reliable months are June–September. May and October can also work on the right days (average highs May 70°F, Oct 62°F). November–April is too cold, with average highs around 43°F. In May, nights average about 50°F, so finish early on mild days and check the overnight low. October is cool, with highs around 62°F, so choose the warmest afternoons.
In Grand Rapids, the most reliable months are June–September. May and October can also work on the right days (average highs May 70°F, Oct 61°F). November–April is too cold, with average highs around 42°F. In May, nights average about 49°F, so finish early on mild days and check the overnight low. October is cool, with highs around 61°F, so choose the warmest afternoons.
In Sault Ste. Marie, the most reliable months are July–August. June and September can also work on the right days (average highs Jun 73°F, Sep 68°F). October–April is too cold, with average highs around 37°F. In May, nights average about 41°F, too cold for the coating to dry and cure overnight. In June and September, nights average about 49°F, so finish early on mild days and check the overnight low.
Best time to fertilize or treat a lawn in Michigan
In Detroit, the most reliable months are May–October. April can also work on the right days (average highs Apr 59°F). November–March is too cold, with average highs around 40°F. April is cool, with highs around 59°F, so choose the warmest afternoons.
In Grand Rapids, the most reliable months are May–October. April can also work on the right days (average highs Apr 58°F). November–March is too cold, with average highs around 39°F. April is cool, with highs around 58°F, so choose the warmest afternoons.
In Sault Ste. Marie, the most reliable months are May–September. October can also work on the right days (average highs Oct 54°F). November–April is too cold, with average highs around 34°F. October is cool, with highs around 54°F, so choose the warmest afternoons.
How the weather differs across Michigan
| Place | Hottest month avg high | Coldest month avg low | Rain per year | Last spring freeze | First fall freeze |
|---|---|---|---|---|---|
| Detroit | 84°F | 19°F | 34 in | April 20 | October 27 |
| Grand Rapids | 83°F | 19°F | 39 in | April 29 | October 20 |
| Sault Ste. Marie | 77°F | 8°F | 34 in | May 9 | October 11 |
Of the places above, Detroit has the most good months for staining, painting and concrete combined (15 job-months), and Sault Ste. Marie has the fewest (10).
Monthly weather in Detroit
| Month | Avg high | Avg low | Wet days* | Rain | 3 PM humidity | Freezing nights |
|---|---|---|---|---|---|---|
| January | 32°F | 19°F | 6 | 2.2 in | 66% | 27 |
| February | 35°F | 21°F | 5 | 2.1 in | 60% | 25 |
| March | 46°F | 29°F | 6 | 2.4 in | 51% | 21 |
| April | 59°F | 39°F | 7 | 3.3 in | 45% | 6 |
| May | 70°F | 50°F | 8 | 3.7 in | 48% | 0 |
| June | 80°F | 60°F | 6 | 3.3 in | 49% | 0 |
| July | 84°F | 64°F | 6 | 3.5 in | 50% | 0 |
| August | 81°F | 63°F | 6 | 3.3 in | 52% | 0 |
| September | 74°F | 56°F | 6 | 3.2 in | 51% | 0 |
| October | 62°F | 44°F | 6 | 2.5 in | 53% | 2 |
| November | 49°F | 34°F | 6 | 2.6 in | 58% | 14 |
| December | 37°F | 25°F | 5 | 2.3 in | 65% | 24 |
*Days with 0.1 inch of rain or more; column notes.
Monthly weather in Grand Rapids
| Month | Avg high | Avg low | Wet days* | Rain | 3 PM humidity | Freezing nights |
|---|---|---|---|---|---|---|
| January | 31°F | 19°F | 7 | 2.5 in | 71% | 28 |
| February | 34°F | 20°F | 6 | 2.1 in | 65% | 25 |
| March | 45°F | 27°F | 6 | 2.4 in | 54% | 23 |
| April | 58°F | 37°F | 8 | 4.0 in | 47% | 10 |
| May | 70°F | 49°F | 8 | 4.0 in | 48% | 1 |
| June | 79°F | 58°F | 6 | 3.9 in | 50% | 0 |
| July | 83°F | 63°F | 6 | 3.9 in | 51% | 0 |
| August | 81°F | 61°F | 6 | 3.5 in | 53% | 0 |
| September | 74°F | 53°F | 6 | 3.4 in | 53% | 0 |
| October | 61°F | 42°F | 8 | 4.0 in | 56% | 4 |
| November | 47°F | 33°F | 7 | 3.1 in | 62% | 16 |
| December | 36°F | 25°F | 7 | 2.5 in | 70% | 26 |
Monthly weather in Sault Ste. Marie
| Month | Avg high | Avg low | Wet days* | Rain | 3 PM humidity | Freezing nights |
|---|---|---|---|---|---|---|
| January | 24°F | 8°F | 7 | 2.2 in | 69% | 30 |
| February | 26°F | 9°F | 5 | 1.5 in | 64% | 28 |
| March | 36°F | 18°F | 5 | 1.8 in | 56% | 28 |
| April | 49°F | 30°F | 7 | 2.6 in | 49% | 18 |
| May | 63°F | 41°F | 6 | 2.6 in | 48% | 4 |
| June | 73°F | 50°F | 6 | 2.9 in | 54% | 0 |
| July | 77°F | 55°F | 6 | 3.1 in | 56% | 0 |
| August | 76°F | 55°F | 7 | 3.2 in | 57% | 0 |
| September | 68°F | 49°F | 8 | 3.9 in | 60% | 0 |
| October | 54°F | 39°F | 10 | 4.4 in | 64% | 7 |
| November | 41°F | 28°F | 9 | 3.4 in | 69% | 20 |
| December | 31°F | 17°F | 8 | 2.8 in | 73% | 29 |
Source: NOAA NCEI U.S. Climate Normals 1991–2020 for DETROIT METRO AP, GRAND RAPIDS, SAULT STE MARIE SANDERSON FLD. See how the ratings work and how late in fall you can stain, paint or seal.
Frequently asked questions
When is the best time to stain a deck in Michigan?
In Detroit, May–September. In Grand Rapids, May–September. In Sault Ste. Marie, June–August.
When is the last frost in Michigan?
Detroit: around April 20; Grand Rapids: around April 29; Sault Ste. Marie: around May 9.
Can you pour concrete in winter in Michigan?
Yes, with cold-weather practices: Detroit averages about 77 freezing nights from December to February, so fresh concrete needs insulated blankets, a heated enclosure or an accelerated mix, and must not freeze in the first 48 hours. Many homeowners wait for spring.
What months are best for sealing a driveway in Michigan?
In Detroit, June–September. In Grand Rapids, June–September. In Sault Ste. Marie, July–August.