The national gasoline price fell 1 cent to $2.83 for the week ending Sept. 4, as demand remains fairly high, according to AAA. The national average is now 4 cents lower than a month ago and 19 cents higher than a year ago.

Gasoline demand has reached its highest level on record with 9.89 barrels for the week ending Aug. 24, according to the U.S. Energy Information Administration. That spike isn't expected to continue, said Jeanette Casselano, AAA spokesperson.

"With summer in the rearview mirror, demand is expected to significantly drop off in the coming weeks which means motorists can expect to see gas prices steadily decline," Casselano said. "AAA expects the national average to hit $2.70 or less this fall."

States with the most expensive gasoline include Hawaii ($3.78), California ($3.62), Washington ($3.38), Alaska ($3.31), Oregon ($3.26), Idaho ($3.25), Nevada ($3.19), Utah ($3.18), Pennsylvania ($3.05), and Connecticut ($3.04).

States with the biggest monthly changes include Indiana (down 16 cents), Kentucky (down 12 cents), Illinois (down 11 cents), Delaware (down 10 cents), Ohio (down 10 cents), Idaho (up 10 cents), Utah (up 10 cents), Alaska (down 9 cents), South Dakota (down 8 cents), and Michigan (down 8 cents).

Meanwhile, the average price of a gallon of diesel increased 2.6 cents to $3.252, which is 49.4 cents higher than it was a year ago.