Planning for the weather is a good way to make your trip to Isle of Raasay relaxing and enjoyable, especially when you’re splurging. The hottest months are usually July and August with an average temp of 55°F, while the coldest months are January and February with an average of 42°F. The rainiest months in Isle of Raasay are October, December, November, and January, with each month seeing an average of 8 inches of rainfall.