Sunday's monsoon rains brought the Phoenix region treacherous flooding that prompted numerous water rescues and historically low temperatures during the hottest time of the year. The midday storm flooded roads and washes in parts of Maricopa and Pinal counties, according to the National Weather Service, which issued a flash-flood warning for parts of both counties. It was the biggest, wettest storm of this years monsoon, which began June 15, said meteorologist Mark O'Malley. It covered a wider area and dropped more rain than any other so far, and lifted the total yearly rainfall above Arizona's average, he said. See photos in the gallery above courtesy of CBS.