The rest of the nation has joined Maine in paying $4 a gallon for gas.
AAA and the Oil Price Information Service say the national average price for a gallon of regular gasoline rose to $4.005 overnight from $3.988.
But consumers in many parts of the country, including Maine, already have been paying that price, or more, for some time.
Gas is expected to keep climbing, putting greater pressure on consumers and businesses, because the price of oil is soaring in futures markets. Light, sweet crude shot up nearly $11 a barrel Friday and approached $140 for the first time.
In Maine, gas topped $4 a gallon last week. AAA says the latest average is $4.025 in Maine.