Klimek approached the first woman, who was in her 30s, on Throstle Street on 29 November, police said.
He gripped hold of her coat and hit her in the face before grabbing her throat and raping her. As he left the scene, he threatened her.
Two weeks later, Klimek approached a second woman before hitting her in the face and then raping her.
Police said the woman, who “screamed for help and attempted to fight back”, slipped “in and out of consciousness as he continued to assault and rape her”.
Klimek, of Ingleby Close, Blackburn, was arrested and charged.
Det Con Hannah Tofalos described him as “dangerous” and “abhorrent”.
She said: “The judge described Klimek as a ‘lying, vicious coward’ in his sentencing remarks, and I can only echo that sentiment.
“Klimek carried out a sustained and brutal attack on one of his victims, before casually walking away from the scene.
“He is a sexual predator who chose to attack his victims in the horrific way he did.”
