The nation's average gasoline prices have jumped 10 cents to $2.75 per gallon in the past 15 days due to increasing demand and new gas taxes in 13 states, according to AAA.

The July 8 price is 4 cents higher than a week ago, 1 cent lower than a month ago, and 11 cents cheaper than a year ago.

"The only motorists seeing relief at the pump are in a handful of states in the West Coast and Rockies regions where prices are trending cheaper, but still rank among the most expensive in the country," said Jeanette Casselano, AAA spokesperson. "The majority of motorists can expect more expensive gas prices throughout July, but the national average is still not likely to hit $3 per gallon."

States that have introduces new gasoline taxes include California, Connecticut, Illinois, Indiana, Maryland, Michigan, Montana, Nebraska, Ohio, Rhode Island, South Carolina, Tennessee, and Vermont.

States with the largest weekly increases include Illinois (14 cents), Florida (13 cents), Ohio (9 cents), Michigan (7 cents), Georgia (6 cents), Alabama (6 cents), Indiana (5 cents), Texas (5 cents), Maryland (5 cents). and Tennessee (5 cents).

States with the lowest average price include Mississippi ($2.34), Arkansas ($2.36), Louisiana ($2.38), Alabama ($2.39), South Carolina ($2.41), Oklahoma ($2.41), Missouri ($2.46), Tennessee ($2.46), Texas ($2.47), and Virginia ($2.47).

Meanwhile, the average price of a gallon of diesel increased 1.3 cents to $3.055, which is 18.8 cents lower than a year ago, according to the U.S. Energy Information Administration.