Mackinac Island, MI weather in August
Expect mild weather with frequent rain in Mackinac Island in August, with highs near 77°F and lows near 57°F. Rain falls on about 10 days. It is one of the warmest months in Mackinac Island. Great for outdoor plans.
- Normal high
- 77°F
- Normal low
- 57°F
- Wet days
- 10
- 3.3 in total
- Muggy days
- 4
- dew point 65°F+
How August changes from start to finish
| August 1 | August 31 | |
|---|---|---|
| Normal high | 78°F | 75°F |
| Normal low | 59°F | 54°F |
| Chance of a wet day | 34% | 37% |
| Sunrise / sunset | 6:21 am / 9:08 pm | 6:58 am / 8:19 pm |
| Daylight | 14.8 h | 13.3 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 August day
- 6 am56°Fdew point 54°F
- 9 am68°Fdew point 59°F
- Noon74°Fdew point 57°F
- 3 pm76°Fdew point 57°F
- 6 pm73°Fdew point 57°F
- 9 pm64°Fdew point 58°F
NOAA hourly normals (local standard time) from Pellston Rgnl Airport (21 mi away); average wind 6 mph.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F17 of 31
- Beach dayshigh 80-95°F, under 0.05 in of rain, afternoon wind under 15 mph6 of 31
- Hot dayshigh 90°F or more1 of 31
- Muggy daysdaily mean dew point 65°F or more4 of 31
- Wet daysat least 0.01 in of rain or melted snow10 of 31
- Notable rainat least 0.10 in6 of 31
- Freezing nightslow 32°F or below0 of 31
- Snow on the groundsnow depth 1 in or more0 of 31
Average days per August, counted from daily records for each year 1991-2020.
Rain in August
Normal precipitation is 3.3 in; a dry August brings about 2.2 in and a wet one about 3.9 in (25th and 75th percentiles). About 2 days bring half an inch or more, and about 1 an inch or more.
How August varies from year to year
- Warmest August, 1991-20201991: average high 81°F
- Coolest August1997: average high 73°F
- Wettest August1994: 7.5 in
- Driest August2019: 0.5 in
- Highest reading97°F (August 1, 2006)
- Lowest reading40°F (August 16, 1992)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
August compared with July and September
| July | August | September | |
|---|---|---|---|
| Normal high | 77°F | 77°F | 70°F |
| Normal low | 58°F | 57°F | 50°F |
| Wet days | 11 | 10 | 13 |
| Comfortable days | 16 | 17 | 15 |
| Daylight | 15.3 h | 14.1 h | 12.5 h |
Highs change by 0°F from July and -7°F into September.
How Mackinac Island ranks in August
- Normal high349th warmest of 378 cities; 8th of 8 in Michigan
- Wet days285th driest of 378
- Comfortable days22nd most of 341
What to pack for Mackinac Island in August
- A rain jacket or umbrella – rain on about 10 days
- Sunglasses and sunscreen – about 14.1 hours of daylight and highs near 77°F
Heating and cooling
August has 45 heating degree days and 100 cooling degree days (base 65°F), 2% of the year's total heating and cooling demand.
Questions
How hot is Mackinac Island in August?
The normal high is 77°F and the normal low is 57°F. From 1991 to 2020 the hottest August reading was 97°F (August 1, 2006).
Does it rain a lot in Mackinac Island in August?
About 10 days in August have at least 0.01 in of precipitation, and the normal total is 3.3 in. The wettest August in 1991-2020 was in 1994 (7.6 in); the driest was in 2019 (0.5 in).
Is August a good time to visit Mackinac Island?
August ranks 3rd of 12 months on our comfort score for Mackinac Island (74 out of 100). It has about 17 comfortable days and about 1 day at 90°F or hotter. 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).