Storage devices and an operating method of a storage controller configured to control storage devices. For example, the storage device may include a non-volatile memory and a storage controller. The non-volatile memory includes a first block and a second block, the first block including first memory cells each storing N-bit data, and the second block including second memory cells each storing M-bit data. During a read reclaim operation on the first block, the storage controller determines read hot data stored in the first block and writes the read hot data to the second block. The storage controller may select a first word line corresponding to a first page in which a number of error bits is equal to or greater than a threshold value and determine data stored in a page corresponding to a second word line adjacent to the first word line as the read hot data.