Mackinac Island, MI weather in September
September in Mackinac Island: mild, with frequent rain. Highs 70°F, lows 50°F, about 13 days with rain.
- Normal high
- 70°F
- Normal low
- 50°F
- Wet days
- 13
- 3.4 in total
- Muggy days
- 1
- dew point 65°F+
How September changes from start to finish
| September 1 | September 30 | |
|---|---|---|
| Normal high | 74°F | 64°F |
| Normal low | 54°F | 45°F |
| Chance of a wet day | 39% | 47% |
| Sunrise / sunset | 6:59 am / 8:17 pm | 7:35 am / 7:21 pm |
| Daylight | 13.3 h | 11.8 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Eastern Time).
A typical September day
- 6 am50°Fdew point 47°F
- 9 am60°Fdew point 53°F
- Noon66°Fdew point 52°F
- 3 pm68°Fdew point 51°F
- 6 pm64°Fdew point 52°F
- 9 pm56°Fdew point 51°F
NOAA hourly normals (local standard time) from Pellston Rgnl Airport (21 mi away); average wind 7 mph.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F15 of 30
- Beach dayshigh 80-95°F, under 0.05 in of rain, afternoon wind under 15 mph3 of 30
- Hot dayshigh 90°F or more0 of 30
- Muggy daysdaily mean dew point 65°F or more1 of 30
- Wet daysat least 0.01 in of rain or melted snow13 of 30
- Notable rainat least 0.10 in7 of 30
- Freezing nightslow 32°F or below0 of 30
- Snow on the groundsnow depth 1 in or more0 of 30
Average days per September, counted from daily records for each year 1991-2020.
Rain in September
Normal precipitation is 3.4 in; a dry September brings about 2.2 in and a wet one about 4.4 in (25th and 75th percentiles). About 2 days bring half an inch or more, and about 1 an inch or more.
How September varies from year to year
- Warmest September, 1991-20202004: average high 75°F
- Coolest September1993: average high 65°F
- Wettest September1996: 5.9 in
- Driest September2004: 1.0 in
- Highest reading92°F (September 1, 2000)
- Lowest reading24°F (September 29, 1992)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
September compared with August and October
| August | September | October | |
|---|---|---|---|
| Normal high | 77°F | 70°F | 56°F |
| Normal low | 57°F | 50°F | 39°F |
| Wet days | 10 | 13 | 16 |
| Comfortable days | 17 | 15 | 6 |
| Daylight | 14.1 h | 12.5 h | 10.9 h |
Highs change by -7°F from August and -14°F into October.
Nearby alternatives in September
- Drier: Sister Bay, WI129 mi · high 68°F · 10 wet days
How Mackinac Island ranks in September
- Normal high354th warmest of 378 cities; 8th of 8 in Michigan
- Wet days351st driest of 378
- Comfortable days65th most of 342
What to pack for Mackinac Island in September
- A rain jacket or umbrella – rain on about 13 days
Heating and cooling
September has 200 heating degree days and 35 cooling degree days (base 65°F), 3% of the year's total heating and cooling demand.
Questions
How hot is Mackinac Island in September?
The normal high is 70°F and the normal low is 50°F. From 1991 to 2020 the hottest September reading was 92°F (September 1, 2000).
Does it rain a lot in Mackinac Island in September?
About 13 days in September have at least 0.01 in of precipitation, and the normal total is 3.4 in. The wettest September in 1991-2020 was in 1996 (5.9 in); the driest was in 2004 (1.0 in).
Is September a good time to visit Mackinac Island?
September ranks 4th of 12 months on our comfort score for Mackinac Island (68 out of 100). It has about 15 comfortable days. The best month is June.
Where the numbers come from
- Temperature, rain, snowfall and snow depth: Cheboygan (USC00201492), 15 mi SSE of the city center, 588 ft . NOAA normals and daily records, 1991-2020.
- Frost dates: St Ignace Mackinac Br (USC00207274), 5.0 mi W of the city center, 595 ft . NOAA normals and daily records, 1991-2020.
- Humidity and wind by hour: Pellston Rgnl Airport (USW00014841), 21 mi SSW of the city center, 705 ft (107 ft higher than the city). NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Pellston Regional Arpt Of Emmet County Arpt (727347-14841), 21 mi SSW of the city center, 706 ft (108 ft higher than the city). Hourly observations, 1991-2020.
- Not available for this location: cloud cover (no station close enough or similar enough in elevation).