Average retail gasoline prices in Missouri have risen 1.8 cents per gallon in the past week, averaging $3.46 per gallon Monday, according to gasoline website GasBuddy's daily survey of 3,940 gas outlets in Missouri.

With refinery maintenance wrapping up, prices should decline around Memorial Day or the beginning of June, said Patrick DeHaan, senior petroleum analyst for GasBuddy.com in Chicago, in a news release.

But, as with everything, there are "some asterisks" if refinery problems occur, DeHaan said.

The national average rose 2.5 cents per gallon in the past week to $3.65 a gallon. Gas prices around the Cape Girardeau area range from $3.30 to $3.55, the GasBuddy website shows.

Locations with higher prices are likely on the interstate, and going inland a bit will net motorists a lower fuel bill, DeHaan said in the release.

Compared to other areas of the state, Cape Girardeau prices are "all over the map," partly because of its proximity to other states, DeHaan said, although there are many factors that go into gas prices.

Including the change in gas prices in Missouri during the past week, prices Sunday were 9.1 cents per gallon higher than the same day one year ago and are 6.7 cents per gallon higher than a month ago, the release said. The national average has increased 12.9 cents per gallon during the last month and stands 16.5 cents per gallon higher than this day one year ago.