The floods brought chaos to northern provinces just as authorities were declaring wildfires had been brought under control after raging through southern coastal regions for two weeks.
The greatest damage was observed in the Bozkurt district, where emergency workers were searching demolished buildings for the missing.
Torrents of water tossed dozens of cars and heaps of debris along streets, destroyed buildings and bridges, closed roads and cut off electricity to hundreds of villages.
More than 2,000 people were evacuated from affected areas, some with the help of helicopters and boats, the Disaster and Emergency Management Directorate (AFAD) said.