Planning for the weather is a good way to make your trip to Beaver Island relaxing and enjoyable, especially when you're splurging. The hottest months are usually July and August, with an average temperature of 17°C, while the coldest months are February and January, with an average of -5°C. The snowiest months in Beaver Island are January, November, February and March, with each month seeing an average of 30 cm of snowfall.