Norovirus Incubation Period: A Summary. When a person becomes infected with norovirus, the virus begins to multiply within the small intestine. After approximately 1 to 2 days, norovirus symptoms can appear.This period between the norovirus transmission and the start of norovirus symptoms is known as the norovirus incubation period..fter approximately 1 to 2 days, norovirus symptoms can appear. This period between the norovirus transmission and the start of norovirus symptoms is known as the norovirus incubation period..