SeasonMapMackinac Island weather by month
United States
The best time to visit Mackinac Island is July to September — 89/100 in August, 23°C and 9 rainy days. The best season is summer, June to August (85/100 on average).
The worst month is January at 28/100 — freezing, a little rain, clean air. See January →
Updated September 2026 · climate normals from ERA5 reanalysis
Planning the wider trip? Best time to visit United States →
Mackinac Island, month by month
Comfort score out of 100 for the kind of trip Mackinac Island is best for, the average high, rainy days and hours of sun a day from the climate normals, and how busy it tends to be.
| Month | Score | Tier | High | Rain | Sun | Crowds | On |
|---|---|---|---|---|---|---|---|
| JanJanuary | 28 | F | -2°C | 10 d | 4 h | Busy | 2 |
| FebFebruary | 36 | F | -2°C | 10 d | 6 h | Quiet | 2 |
| MarMarch | 46 | F | 2°C | 10 d | 8 h | Busy | 2 |
| AprApril | 55 | D | 6°C | 12 d | 9 h | Shoulder | 4 |
| MayMay | 74 | B | 13°C | 9 d | 11 h | Shoulder | 5 |
| JunJune | 79 | B | 20°C | 9 d | 12 h | Peak | 4 |
| JulJuly | 87 | A | 24°C | 8 d | 12 h | Peak | 5 |
| AugAugust | 89 | A | 23°C | 9 d | 11 h | Peak | 4 |
| SepSeptember | 82 | A | 20°C | 10 d | 10 h | Peak | 4 |
| OctOctober | 62 | C | 14°C | 13 d | 7 h | Busy | 4 |
| NovNovember | 42 | F | 6°C | 12 d | 5 h | Peak | 3 |
| DecDecember | 30 | F | 1°C | 12 d | 4 h | Busy | 2 |
What's on in Mackinac Island through the year
Festivals, natural spectacles, holidays and the seasons to watch out for — curated and sourced. The month pages carry the detail.
- January
- No motor vehicles1 Jan – 31 DecRule
- April
- The horses come back20 Apr – 15 May (usually)Opening
- Island season opens25 Apr – 20 May (usually)Opening
- May
- Black fly and stable fly weeks15 May – 15 Jul (usually)Hazard
- Grand Hotel's season1 May – 31 Oct (usually)Season
- June
- Lilac Festival1–16 Jun (usually)Festival
- July
- The Mackinac yacht races10–30 Jul (usually)Festival
- High summer1 Jul – 25 AugSeason
- August
- Mackinac Bridge Walk30 Aug – 8 Sep (usually)Festival
- September
- Fall colour25 Sep – 20 Oct (usually)Nature
- October
- Somewhere in Time weekend20 Oct – 1 Nov (usually)Festival
- November
- Winter shutdown1 Nov – 25 Apr (usually)Closure
Crowds in Mackinac Island in August
How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.
Peak crowdsHigh summer, Mackinac Bridge Walk, Summer break in United States(estimated)
Peak crowdsBusyShoulder seasonQuiet