Average retail gasoline prices in Michigan have fallen 11.4 cents per gallon in the past week, averaging $3.19 per gallon Sunday.

This compares with the national average that has fallen 4.3 cents per gallon in the past week to $3.23 per gallon, according to gasoline price website MichiganGasPrices.com.

Including the change in gas prices in Michigan during the past week, prices Sunday were 21.4 cents per gallon higher than the same day one year ago and are 9.6 cents per gallon lower than a month ago. The national average has decreased 13.4 cents per gallon during the past month and stands 26.4 cents per gallon higher than this day one year ago.

“Gas prices across much of the nation continue their downward move, bringing the national average for a gallon down to its lowest level since late February,” said Patrick DeHaan, a senior petroleum analyst with GasBuddy.com.

“While some motorists are thinking these falling gasoline prices are nice, I’ll unpleasantly remind them that gasoline prices will still set record highs this Christmas across much of America — motorists have never seen average prices this high on Christmas.

As prices typically reach a low point during early winter, this sets up a troubling start to 2012 in terms of gasoline prices. Summer gasoline prices typically are 80 to 120 cents per gallon higher than where prices stand around Christmas,” DeHaan said.