Housing prices dipped for the second straight month in September, falling 1.1% from the prior month, according to the CoreLogic (CLGX) home price index. Single-family home prices declined 4.1% from a year earlier and decreased 1.1% from September 2010, excluding distressed sales. The 0.4% decline in August prices was the first month-over-month dip in four months. Prices are expected to continue their decline through the winter on waning housing demand, CoreLogic Chief Economist Mark Fleming said Monday. "Even with low interest rates, demand for houses remains muted," Fleming said. "Distressed sales remain a significant share of homes that do sell and are driving home prices overall." Twelve states saw price increases in September from a year earlier, including a 7% gain in West Virginia, 3.8% in Wyoming, 3.6% in South Dakota, 3.5% in Maine and 3.1% in North Dakota. Nevada prices fell the most from September 2010 with a 12.4% decline, followed by Illinois with a 9.2% drop, Arizona at 9%, Minnesota at 8.3% and Georgia with a 7.2% decrease. Of the 10 largest metro areas, both New York (2.2%) and Washington D.C. (1%) saw increases, while the largest declines came in Chicago at 9.7% and Phoenix with an 8% drop. Home prices in September were down 31.2% from peak levels in April 2006, and down 21.9% excluding distressed sales. Write to Andrew Scoggin. Follow him on Twitter @ascoggin.