Autumn comes and leaves start to change colour on trees and ground in early September. This process lasts two to three weeks before leaves fall from the trees, unless an autumn storm rips them off earlier than usual.

Winter typically begins in early November when the average daily temperature permanently drops below zero. The first snow often falls in October. In Kuusamo, the snow-covered period usually lasts from mid-October to May. On average, 85 cm of snow accumulates during the winter. Kuusamo does not experience a true polar night like in northern Lapland, but the days are very short from November to January. In December, there are about three hours of daylight, and in November and January, about five hours. Although Kuusamo does not have a complete polar night, the pastel shades of twilight and the blue moment color the snowy landscape. The coldest periods in Kuusamo typically occur in January and early February. In the river valley of Oulanka National Park, it can be over 10 degrees colder than in the Ruka-Kuusamo area. The lowest temperature recorded at Kiutaköngäs is -46 °C.

Winter trekking and staying overnight in the wild require proper equipments. Early spring is the best ski-season, and usually lasts from the beginning of February to the end of April. Typically, in April and May, the spring snow begins to soften, making it impossible to move in the forest terrain with skis or snowshoes. Spring usually arrives in Kuusamo in the last week of April as the days lengthen, but it is not uncommon for the trails to be covered with snow even in June.

In May, the melting snow makes the trails wet and slushy, so rubber boots or waterproof shoes are recommended. In Oulanka National Park, the spring flood usually peaks in mid-May, causing the river levels to rise rapidly. Due to the flood, some trails, such as the Karhunkierros hiking trail, may be temporarily impassable. Thawing can also temporarily close some gravel roads leading to the trails. Information about the flood and trail conditions is provided on the What's new -page..

Summer begins after Mid-June. Insects such as mosquitoes (Culicidae Family) hatch around mid-June or late June. Sand flies (Simuliidae Family), horseflies (Tabanidae Family) and Ceratopogonidae follow close behind. There have been quite few mosquitoes in recent years and visitors have been able to enjoy Kuusamo in peace and quiet, but you need to be prepared well to mosquitoes while hiking in every summer.

Canoeing routes in Oulanka National Park