Early autumn · Weather & things to do
Mackinac Island in September
Mackinac Island cools off: highs slip to 66°F (19°C), from 72°F in August, with lows of 54°F (12°C) and about 3.6 in (92 mm) of rain.
September opens the best stretch on our comfort score, at 83/100 (the top score of the year).
- Avg high
- 66°F (19°C)
- Avg low
- 54°F (12°C)
- Rain
- 3.6 in (92 mm)
- Humidity
- 81%
- Cloud cover
- 61%
- Daylight
- ~12 h 18 min
- Comfort score
- 83/100 · Great
What September feels like
Highs near 66°F (19°C) make for comfortable sightseeing weather.
After dark, temperatures fall to about 54°F (12°C).
Some rain is likely, about 3.6 in (92 mm) in the month, so pack for a shower or two.
Plan around September
September is one of Mackinac Island's best months on the climate data.
- Inside the wettest three-month stretch, August – October.
- Opens the best-scoring stretch on our comfort score: June and September.
- Last of the best-scoring months: by October, the score drops to 57/100.
- Comfort improves from 76/100 in August to 83/100.
- September sits inside the May – Sep window our Great Lakes Hidden Gems route recommends.
- September sits inside the Jun – Sep window our Michigan Lake Shore route recommends.
What to pack for September
- A warm layer for eveningslows near 54°F
- Packable rain jacket or umbrellaa shower or two is likely
- Comfortable walking shoesmost places below are best reached on foot or with short walks
What to do in Mackinac Island in September
September is good outdoor weather here, so these picks lean toward the open air.
The Pink Pony
Waterfront restaurant and bar at the Chippewa Hotel, famous for whitefish.
Why now September scores 83/100 for comfort, good conditions for being outside.
Arch Rock
Limestone arch 146 ft above the water, reached by stairs or a bluff road.
Why now Highs near 66°F and 3.6 in of monthly rain make this an easy outdoor pick.
Mackinac Island Carriage Tours
Narrated horse-drawn carriage tour of the island's sights.
Fort Mackinac
18th-century fort above the harbor with cannon firings and costumed interpreters.
Grand Hotel
1887 hotel with the world's longest porch and formal gardens.
Why now One to do outside while the weather is on your side.
Nearby in September
- Traverse City in September~89 mi · highs 68°F, 3.4 in rain · 2°C (3°F) warmer by day, about as wet
- Sleeping Bear Dunes in September~103 mi · highs 65°F, 3.4 in rain · similar daytime temperatures, about as wet
- Door County in September~138 mi · highs 69°F, 3.4 in rain · 2°C (3°F) warmer by day, about as wet
- Frankenmuth in September~179 mi · highs 72°F, 2.9 in rain · 4°C (6°F) warmer by day, drier
NASA POWER 2001–2025 monthly averages on a ~50 km grid. Comfort scores weigh temperature, rain, humidity and cloud: see how we score each month. Check a forecast before you go.
Mackinac Island in September: quick answers
Is September a good time to visit Mackinac Island?
Yes. On the climate data it's one of the best months, scoring 83/100. Expect highs of 66°F (19°C) and 3.6 in (92 mm) of rain. September is inside the May – Sep window our Great Lakes Hidden Gems route recommends.
How hot is Mackinac Island in September?
Average highs are 66°F (19°C) and average lows 54°F (12°C), making it the 3rd-warmest month by daytime highs.
Does it rain a lot in Mackinac Island in September?
Some: about 3.6 in (92 mm) of rain falls across September on average, the 2nd-wettest month of the year. The annual total is about 34.4 in (875 mm).
What should I pack for Mackinac Island in September?
Bring a warm layer for evenings (lows near 54°F), packable rain jacket or umbrella (a shower or two is likely) and comfortable walking shoes (most places below are best reached on foot or with short walks).
More on Mackinac Island
Routes in season in September
- Great Lakes Hidden Gems May – Sep
- Michigan Lake Shore Jun – Sep
Planning Mackinac Island in September?
Plan it together in TripsCircle: one itinerary, one shared packing list and costs split as you go.