Autumn begins in September. The trees lose their leaves in October, and the flowers disappear. During November, fresh water and rivers start to freeze, and the landscape is covered with snow. Only the spruce forest stays green throughout the winter. In the winter, the sun is low on the horizon, and is only visible for a few hours. Heating through sunlight is limited because of Mo i Rana's high-latitude location. Mountains block the sunlight when the sun is low on the horizon, which means that the sun is not visible at all during the month of December. There are normally two to three very cold periods in the winter with temperature dipping close to minus 30 °C. The cold periods normally last 3–7 days. But in the summer has midnight sun and there is no polar night in December at all. Average precipitation is 1400 mm/year.