The average price of a single-family home fell 0.8% in October from a year earlier, and prices dropped in all 20 largest metropolitan areas during the month, according to the Standard & Poor’s/Case-Shiller index. The ratings agency’s benchmark 20-city composite index has declined for five consecutive months and prices are now back at levels comparable to the middle of 2003. The 20-city composite index declined 0.7% in September and was down 1.5% for the third quarter. The 10-city composite index inched up 0.2% for October from the year ago, buoyed by increases in Los Angeles, San Diego, San Francisco and Washington. Meanwhile, prices in six markets — Atlanta, Charlotte, Miami, Portland, Ore., Seattle and Tampa — dipped to the lowest level since the current declines began in 2006 and 2007, according to Standard & Poor’s. “The double-dip is almost here, as six cities set new lows for the period since the 2006 peaks. There is no good news in October’s report. Home prices across the country continue to fall,” said David Blitzer, chairman of the index committee. “The trends we have seen over the past few months have not changed. The tax incentives are over and the national economy remained lackluster in October.” The 10-city index fell 1.2% on a non-seasonally adjusted basis in October from September and 20-city composite index dropped 1.3%, with declines in all 20 metropolitan areas month over month. Atlanta saw the steepest decline at 2.9% and three-fourths of the areas experienced decreases of more than 1%, according to Standard & Poor’s. “Existing homes sales and housing starts have been reported for both October and November, and neither is giving any sense of optimism,” Blitzer said. “On a year-over-year basis, sales are down more than 25% and the months’ supply of unsold homes is about 50% above where it was during the same months of last year. Housing starts are still hovering near 30-year lows. While delinquency rates might have seen some recent improvement, it is only on a relative basis. They are still well above their historic averages, in both the prime and sub-prime markets.” Write to Jason Philyaw.