Oslo
Photo Courtesy of Astrup Fearnley Museeet/Nic Lehoux
Summer is Oslo's peak tourist season, with temperatures highest in July. Wintertime can be lovely if you like snow and a chill in the air—though it is very, very dark in December and January. Overall, May through September is probably the best time to go, unless you've packed all your warm clothes. And the summer nights are short and light—not the complete midnight sun of points farther north, but still very special.