Photo: n8huckins · CC BY-SA 4.0Mackinac Island gets about 88 inches of snow a winter, more than 96% of U.S. towns
July afternoons average 75°. A year here swings 63° from midwinter lows to midsummer highs. Summers stay cool: July afternoons here are cooler than in 98% of U.S. towns. For walks and days out, the stretch from June to September brings highs of 68–75°.
A year in Mackinac Island at a glance
Each month’s typical high and low, and what it brings.
What stands out about Mackinac Island’s climate
Compared with towns across the U.S., with Mackinac Island’s place in Michigan beside it.
What a year in Mackinac Island feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 149 frost-free days a year
In half of years the last 32° night comes by May 16 and the first by October 13. Frost and day counts come from NOAA’s station at St Ignace, MI, 5 miles from the town’s center, at about the same height.
The 2023 USDA map puts Mackinac Island’s center in zone 6a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −8°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
About 88 inches of snow a winter
Snow, measured at Cheboygan, MI, falls mostly in January and December. Precipitation (rain plus melted snow) adds up to 32 inches a year; October is the wettest month and February the driest. Rain or snow falls on about 153 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Mackinac Island
98% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through May.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at St Ignace, MI.
Living with Mackinac Island’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
149 frost-free days in zone 6a. The last frost comes by May 16 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 13.
Months with highs of 62–84° and lows of 40° or more: June, July, August and September. 37 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Mackinac Island from natural hazards, river flooding is the largest share (69%); heat waves, cold waves, winter storms and ice storms together are 21%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Mackinac Island and its neighbors
St. Ignace Township has the coldest January nights next door (11°, 2° colder). Differences under a degree are within what the 5 km grid can tell apart. Tap a town to see its climate.
Climates most like Mackinac Island’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Mackinac Island, MI | 13° | 75° | 32" | 88" |
| Sturgeon Bay, WI | 13° | 77° | 32" | 57" |
| Alfred, NY | 13° | 78° | 40" | 82" |
| Duluth, MN | 5° | 76° | 30" | 56" |
| Woodland Park, CO | 11° | 77° | 22" | 134" |
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value. Snow and frost-free days come from the nearest weather station, so neighbors often share them.
Warmer than it used to be
The last 30 years in Mackinac Island averaged 1.9° warmer than the 1900s. The biggest change is in February (+3.5°).
A bigger shift than in 86% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Mackinac Island compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Mackinac Island’s place among Michigan’s.
Mackinac Island weather by month
Highs, lows and precipitation from NOAA’s grid at Mackinac Island’s center; snow, wet days and snow on the ground from Cheboygan, MI. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 26° | 13° | 1.7" | 24.2" | 16 | 29 | 6° – 28° |
| February | 28° | 12° | 1.2" | 18.1" | 12 | 27 | 5° – 30° |
| March | 37° | 20° | 1.7" | 11.6" | 10 | 21 | 18° – 41° |
| April | 48° | 30° | 2.6" | 4.9" | 12 | 4 | 31° – 46° |
| May | 61° | 41° | 2.9" | 0.1" | 12 | 0 | 45° – 57° |
| June | 70° | 51° | 3.0" | 0.0" | 11 | 0 | 57° – 66° |
| July | 75° | 58° | 3.0" | 0.0" | 11 | 0 | 60° – 70° |
| August | 75° | 58° | 3.1" | 0.0" | 10 | 0 | 62° – 70° |
| September | 68° | 51° | 3.5" | 0.0" | 13 | 0 | 54° – 64° |
| October | 55° | 40° | 4.1" | 0.5" | 16 | 0 | 43° – 54° |
| November | 42° | 31° | 2.6" | 6.2" | 15 | 6 | 30° – 43° |
| December | 32° | 21° | 2.1" | 22.0" | 15 | 20 | 18° – 36° |
| Year | 51° | 35° | 31.5" | 87.6" | 153 | 107 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 5° to 30°. August is the most reliable, staying within 8°.
Where Mackinac Island’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Mackinac Island’s center.
- Snow: Cheboygan, MI.
- Frost, freezing nights, 90° and 100° days, heating and cooling: St Ignace, MI, 5 miles from the town’s center, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Mackinac Island’s climate
What is the weather like in Mackinac Island?
A typical July afternoon reaches 75°, a January night drops to 13°, and about 88 inches of snow falls in a normal winter. Colder January nights than 89% of U.S. towns; cooler July afternoons than 98% of U.S. towns.
How cold does it get in Mackinac Island in winter?
February nights average 12°. About 165 nights a year reach 32° or below and 13 reach 0° or below. In the coldest February of the last 30 years the month averaged 5°.
How much snow does Mackinac Island get?
About 88 inches in a normal winter at Cheboygan, MI, most of it in January and December, with snow on the ground about 107 days a year.
How hot does it get in Mackinac Island?
July, with a typical high of 75°. 90° days are rare: none in a normal year at St Ignace, MI.
When is the first and last frost in Mackinac Island?
In half of years the last spring frost (32°) comes by May 16 and the first fall frost by October 13, about 149 frost-free days, at St Ignace, MI.
What growing zone is Mackinac Island in?
Zone 6a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −8°.
What is the best time of year to visit Mackinac Island?
By one simple rule (highs of 62–84° and lows of 40° or more), June, July, August and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Mackinac Island getting warmer?
Yes: 1991–2020 averaged 1.9° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 86% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Mackinac Island.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.