Quick answer: For June–August, the best destinations are the Mediterranean (Greece, Italy, Croatia), Scandinavia, Iceland, the US national parks and Japan.
Northern-hemisphere summer opens up the Mediterranean, the far north and the great outdoors. These twelve are the best places to spend it.
The 12 best summer destinations
Greek Islands
Island-hopping, beaches and white villages at their best.
Amalfi & Italy
Coastlines, lakes and long Mediterranean evenings.
Croatia
Island-hopping and sailing the Dalmatian Coast.
Spain
Beaches, festivals and northern coolness in the north.
Scandinavia
The midnight sun, fjords and vibrant cities.
Iceland
The accessible summer of hiking and waterfalls.
US National Parks
Yosemite, Yellowstone and the great American road trip.
Canada
The Rockies, lakes and long, mild days.
Japan
Summer festivals (matsuri) and cool northern Hokkaido.
The Baltics
Tallinn, Riga and Vilnius at their liveliest.
The Alps (summer hiking)
Wildflower meadows and hut-to-hut trails.
Newfoundland & Atlantic Canada
Icebergs, whales and rugged coast.
How to choose
For sun and sea, choose the Mediterranean; for long days and cool air, Scandinavia, Iceland or the Alps; for big outdoors, the US and Canadian parks. Book the Mediterranean early — July and August are peak.