The victim was approached by a man outside Kamran newsagents on Burnley Road and sexually assaulted in an alleyway leading to Wellington Road.
It happened at around midday on Tuesday April 3, but police only released details today. (Mon May 21)
Detective Constable Natasha Butterfield, of Calderdale Police, said: “This offence happened in broad daylight and we are hoping that someone will recall seeing a man matching the suspect’s description in the vicinity of Burnley Road or Wellington Road or have some idea of who he may be.
“We are treating this as an isolated incident but take any report of this nature extremely seriously and have been, and are continuing to make a number of enquiries to identify the man involved.”
The suspect is described as white, aged in his late forties to early fifties, with scruffy dark brown hair.
He was wearing dark jeans and a dirty coat and had his face covered with a scarf.
Anyone who has any information that could help officers investigating this offence is asked to call Calderdale district adult Ssafeguarding team via 101, quoting 13180179114.
Information can also be given to independent charity Crimestoppers anonymously on 0800 555 111.