Kastamonu province is the worst-hit area, accounting for 29 of the deaths. Two others died in Sinop on the coast.
The floods caused some buildings to collapse, smashed several bridges, clogged some streets with wrecked cars and cut power supplies.
This month Turkey has also had to battle huge wildfires in the south.
Those fires - which are now under control - forced thousands of locals and tourists to flee Marmaris and surrounding areas. Eight people died and more than 100,000 hectares (247,000 acres) of vegetation was devastated.
