The national average price for a gallon of regular unleaded increase 4 cents to $2.32 and reached a high-water mark for the past six weeks. It has increased for 12 of the past 15 days, reports AAA.

Strong demand, rising exports and declining U.S. crude oil inventory pushed prices higher in 47 states and Washington, D.C.

"As summer moves forward, the days of dropping summer gas prices appear to be behind us for now," said Jeanette Casselano, AAA Spokesperson. "U.S. crude inventories are moving in the opposite direction of demand — a perfect storm for continued price increases heading into August."

States with the 10 lowest gasoline prices include South Carolina ($2.02), Alabama ($2.03), Mississippi ($2.03), Arkansas ($2.06), Missouri ($2.08), Tennessee ($2.09), Oklahoma ($2.09), Louisiana ($2.09), Virginia ($2.09) and Texas ($2.10).

States with the largest monthly increases include Indiana (26 cents), Ohio (20 cents), Michigan (17 cents), Kentucky (15 cents), Florida (13 cents), Oklahoma (13 cents), South Carolina (11 cents), Kansas (11 cents), and Delaware (10 cents). Prices in Washington, D.C. increased 10 cents.

Meanwhile, the national average price for diesel increased 2.4 cents to $2.531. Diesel is now 18.3 cents higher than it was a year ago, according to the U.S. Energy Information Administration.