The incident happened in East Meadow around 5 a.m.
Police say the subject displayed a knife and forcibly raped the woman in the vicinity of 1650 Hempstead Turnpike before fleeing in an unknown direction.
The suspect is described as a black male in his late 20s or early 30s, approimately 5-foot-9. He has a slight beard and was last seen wearing orange basketball shorts, T-shirt and black, gray and white sneakers. He was carrying a blue backpack.
Crime Stoppers is asking anyone who knows the identity of this subject or with any information about this crime to call the toll free hotline 1-800-244-TIPS (8477). All calls will be kept anonymous.