The temperature variation between the summer and winter seasons is high, fluctuating from around –35°C in winter to a maximum of +30°C in summer.
The warmest month is July (15.5oC) and the coldest months are January and February (-12oC). In the Lake Oulu area, precipitation is on average around 530 mm per year. The highest rainfall is in September. In summer it rains around 60–70 mm per month.
The length of daylight time during mid-summer is nearly 24 hours per day and during the darkest period of winter only around 2 hours per day.
There can be strong Aurora Borealis in the area in the winter.