Rovaniemi has two very different peak seasons, each offering something the other cannot.
Winter (November through March) is the classic Lapland season. From late November the daylight shrinks to just a few hours around noon — the polar night, when the sun does not rise above the horizon, runs from early December to mid-January. This is the period of deep snow, northern lights, reindeer sleighs, and Santa Claus tourism. December and early January are the most expensive and crowded times, with Christmas flights from across Europe bringing families to the Santa experience. February and March have excellent snow conditions with slightly more daylight and lower prices — these months are popular with Finnish families for skiing and snowmobile safaris.
Summer (June through August) is the midnight sun season. In June and July the sun does not set, and the light at midnight is eerie, golden, and beautiful. Hiking, canoeing, and fishing are the activities. The city is lively but not overwhelmed by tourists, and prices are significantly lower than in the Christmas period.
Shoulder seasons (April-May and September-October) are the least visited. Spring is remarkable: the snow melts rapidly in April, the river ice breaks up spectacularly, and by May the birch forests are unfurling their leaves. September brings the autumn colours to the fell country — a brief but vivid display. October gets cold and dark fast, and the northern lights begin to return.