Rain was unusually heavy in Mecca on 25 November, as well as in nearby Mina, where many pilgrims stay in vast tent cities. The weather had improved by 26 November, and pilgrims had to face scorching heat on the plain of Mount Arafat for the second day of the Hajj. Hassan Al-Bushra, an epidemiologist at the Cairo office of the World Health Organization, said there is no evidence that the rain would worsen the spread of the H1N1 flu virus, a view shared by the U.S. Centers for Disease Control and Prevention (CDC).