Late spring and early fall are your best bets for quiet islands.

Yes, you’ve got the right idea. Weekday mornings in May or September are exactly when you’ll find the fewest people at most popular island destinations. Summer is peak season, winter holidays are a mess, and even shoulder months get busy on weekends. So if you can swing a Tuesday morning in mid-May, you’re golden. Just double-check that the island you’re visiting actually stays open that time of year — some smaller spots shut down during off-season entirely.