Climateby Month

Mackinac Island, MI climate by month

NOAA 1991-2020 normals · 598 ft elevation

Summers in Mackinac Island are mild; winters are very cold and snowy. Highs peak at 77°F in July and fall to 27°F in January. Wet days are spread through the year, from about 10 to 16 a month. Normal snowfall is about 88 in a year. The most comfortable time to visit is June.

Warmest month
77°F
July normal high
Coldest month
10°F
February normal low
Wet days a year
153
32.0 in of precipitation
Snow a year
87.6 in
normal snowfall

How warm is Mackinac Island?

Normal highs range from 27°F in January to 77°F in July.

0°20°40°60°80° January: normal high 27°F (-3°C), low 11°F (-12°C) 27° 11° February: normal high 29°F (-2°C), low 10°F (-12°C) March: normal high 38°F (3°C), low 18°F (-8°C) April: normal high 49°F (9°C), low 30°F (-1°C) May: normal high 62°F (17°C), low 41°F (5°C) June: normal high 72°F (22°C), low 52°F (11°C) July: normal high 77°F (25°C), low 58°F (14°C) 77° 58° August: normal high 77°F (25°C), low 57°F (14°C) September: normal high 70°F (21°C), low 50°F (10°C) October: normal high 56°F (13°C), low 39°F (4°C) November: normal high 44°F (7°C), low 30°F (-1°C) December: normal high 33°F (1°C), low 21°F (-6°C) JFMAMJJASOND

Bars run from the normal low to the normal high for each month.

How rainy is Mackinac Island?

October has the most wet days (about 16); the year brings about 32 in of precipitation.

January: 16 wet days February: 11 wet days March: 10 wet days 10 April: 12 wet days May: 12 wet days June: 11 wet days July: 11 wet days August: 10 wet days September: 13 wet days October: 16 wet days 16 November: 15 wet days December: 15 wet days JFMAMJJASOND

Wet day: at least 0.01 in of rain or melted snow, counted from daily records 1991-2020.

How much does it snow?

Normal snowfall is 87.6 in a year, most of it in January.

January: 24.2 in of snow 24.2 February: 18.1 in of snow March: 11.6 in of snow April: 4.9 in of snow May: 0.1 in of snow June: 0.0 in of snow 0.0 July: 0.0 in of snow August: 0.0 in of snow September: 0.0 in of snow October: 0.5 in of snow November: 6.2 in of snow December: 22.0 in of snow JFMAMJJASOND

How humid is Mackinac Island?

Muggy days peak in July, at about 4 days.

January: 0 muggy days 0 February: 0 muggy days March: 0 muggy days April: 0 muggy days May: 0 muggy days June: 1 muggy days July: 4 muggy days 4 August: 4 muggy days September: 1 muggy days October: 0 muggy days November: 0 muggy days December: 0 muggy days JFMAMJJASOND

Muggy day: daily mean dew point of 65°F or higher, from hourly observations 1991-2020 at Pellston Regional Arpt Of Emmet County Arpt, 21 mi SSW of the city center (the nearest airport with complete hourly records).

How much daylight?

Daylight ranges from about 8.7 hours in December to 15.7 hours in June.

January: 9.1 hours of daylight February: 10.4 hours of daylight March: 11.9 hours of daylight April: 13.6 hours of daylight May: 14.9 hours of daylight June: 15.7 hours of daylight 15.7 July: 15.3 hours of daylight August: 14.1 hours of daylight September: 12.5 hours of daylight October: 10.9 hours of daylight November: 9.5 hours of daylight December: 8.7 hours of daylight 8.7 JFMAMJJASOND
See all numbers
Monthly climate normals and day counts for Mackinac Island, 1991-2020
MonthHighLowPrecip.Wet daysSnowMuggy daysDaylight
January 27°F11°F 1.8 in16 24.2 in 0 9.1 h
February 29°F10°F 1.3 in11 18.1 in 0 10.4 h
March 38°F18°F 1.8 in10 11.6 in 0 11.9 h
April 49°F30°F 2.8 in12 4.9 in 0 13.6 h
May 62°F41°F 2.9 in12 0.1 in 0 14.9 h
June 72°F52°F 2.9 in11 0.0 in 1 15.7 h
July 77°F58°F 3.1 in11 0.0 in 4 15.3 h
August 77°F57°F 3.3 in10 0.0 in 4 14.1 h
September 70°F50°F 3.4 in13 0.0 in 1 12.5 h
October 56°F39°F 4.1 in16 0.5 in 0 10.9 h
November 44°F30°F 2.6 in15 6.2 in 0 9.5 h
December 33°F21°F 2.1 in15 22.0 in 0 8.7 h

High and low: NOAA 1991-2020 normal daily high and low. Wet days: at least 0.01 in of rain or melted snow. Muggy days: daily mean dew point 65°F or higher.

Best months to visit Mackinac Island

By our comfort score, the best month is June.

Comfort score by month (0-100) and its parts, in days per month
MonthScoreComfortableNotable rainHot or cold
Jan 220529
Feb 270426
Mar 360520
Apr 50276
May 66970
Jun 781761
Jul 741661
Aug 741761
Sep 681570
Oct 49691
Nov 341712
Dec 240625

Score = 40 × share of comfortable days + 25 × share of days without notable rain + 20 × share of days neither hot (90°F+) nor cold (high 40°F or below) + 15 × daylight. How the score works.

Frost dates in Mackinac Island

The last spring frost typically comes around May 7, and the first fall frost around Oct 23, leaving 167 frost-free days in a typical year.

Frost and freeze dates for Mackinac Island
Typical date1 year in 10
Last spring frost (32°F)May 7after May 22
First fall frost (32°F)Oct 23before Oct 6
Last hard freeze (28°F)Apr 25after May 10
First hard freeze (28°F)Nov 3before Oct 21
Frost-free season167 daysunder 146 days

"Typical" is the date with a 50% chance of a later spring frost (or earlier fall frost). Planting after the "1 year in 10" spring date gives a 90% chance of no further frost. The Old Farmer's Almanac publishes 30% dates, which fall between our typical and 1-in-10 dates.

Station: St Ignace Mackinac Br (USC00207274), NOAA 1991-2020 freeze probabilities. Frost dates for every city in Michigan.

Hottest and coldest readings, 1991-2020

The highest reading was 97°F (July 15, 1995); the lowest was -32°F (February 20, 2015).

From the temperature station's daily records with NOAA quality flags removed. Not an all-time record.

Near Mackinac Island

Similar climates elsewhere

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).

Distances from the city center (USGS). Methodology · Report an error