Iceland is a stunningly beautiful place if you enjoy strange and desolate landscapes. The amount of daylight varies dramatically by season. The sun sets briefly each night in June, but the sky doesn't get fully dark before the next sunrise. In the March and September equinoxes, days and nights are of about equal length, as elsewhere in the world. If you go in December, it's almost 20 hours of darkness. Summer is definitely the best time to go, and even then the tourist traffic is still mild.