The Snowman by Jo Nesbo (Harry Hole #7)

When the first snow falls, Harry Hole is confronted by a terrifying murderer who will push him to the edge...
Soon the first snow will come

A young boy wakes to find his mother missing. Outside, he sees her favourite scarf - wrapped around the neck of a snowman.
And then he will appear again

Detective Harry Hole soon discovers that an alarming number of wives and mothers have gone missing over the years.
And when the snow is gone...

When a second woman disappears, Harry's worst suspicion is confirmed- a serial killer is operating on his home turf.
...he will have taken someone else.