‹ Mackinac Island weather by month
Typical August weather
Mackinac Island
Michigan · August
78° days
52° nights
about 6 rainy days · 14 hours of daylight · lake 69°
What to pack
- Light jacket
- Sunscreen
What August feels like
British Landing is where people actually go in, and August is when they do it without much complaint about the cold. Evenings drop off fast, and the porch of the Grand Hotel wants a sweater after dinner whatever the afternoon suggested.
Expect about 6 days with real rain — enough to notice, not enough to plan around. Humidity stays comfortable; the air never feels heavy.
Can you swim?
The lake runs about 69° — brisk but swimmable.
The numbers
| Typical high | 78° |
|---|---|
| Typical low | 52° |
| Days with real rain | 6 |
| Total rain | 2.9 in |
| Humidity | comfortable |
| Water temperature | 69° |
| Sunrise / sunset (mid-month) | 6:38 am / 8:47 pm |