Must-know travel tips for Maine in the summer months (June, July, and August): Essential tips for each coastal town in summer: Portland, Ogunquit, Camden, Rockland, York, Bar Harbor/Acadia National Park, ... What to wear (outfit tips from a local and packing lists), and the best things to do in the summer months: Hiking, sightseeing, lighthouses, best seafood (lobster rolls!), and more.