It forecasts a national 2% rise in 2013 assisted by greater competition among lenders to lend.
However, with inflation running at more than 2%, housing is becoming cheaper in real terms.
New sellers have chopped an average of £7,772 (-3.3%) off asking prices this month. While this is the largest monthly decrease ever reported by Rightmove, it follows an established pattern of December drops over the previous eight years.
Miles Shipside, director and housing market analyst at Rightmove, said: “December is the most likely month for sellers coming to market to get very real about the price they ask for their home.
“This year they’ve gone a bit further than ever before, though in truth it is symptomatic of the ‘all or nothing’ pattern of 2012.
"This summer also saw big falls with the distractions of the Jubilee and the Olympics, though prices did rebound in October. It seems that sellers who come to market at times when they know that buyers’
attention is focused on other events realise that their prices have to be extra keen in order to compete.
"Many who put their property up for sale this close to the festive season will have a very good and pressing reason to sell, so Christmas will have come early for those buyers who have been able to bag a bargain.”