The best time to visit Arran is from April to the end of September. This is when the weather is usually better (though it is Scotland!) and businesses and Arran attractions are open. Many of the businesses including restaurants and cafes, are shut from October to April so for the full experience it's best to go outside of those months. If you're just visiting for a hike or to enjoy a cosy weekend then any time is a good time to visScottishn!