Winter can be tough in northern Sweden. Some days the temperature can drop to minus 27 or minus 30 degrees Celsius. It is cold outside. It snows a lot as well during winter.
Darkness is one of the challenges during winter. In northern Sweden there is only sunlight for about 4 hours in winter. 21 December is the winter solstice or the day when we have almost no sunlight at all. It is the darkest day of the year. After that the days are getting brighter and brighter.