The nation's average gasoline price fell 5 cents to $2.57 per gallon, especially in Texas, where Hurricane Harvey made landfall a month ago, according to AAA.

Gasoline is still significantly higher than a month ago (22 cents) and a year ago (36 cents), but is falling on a daily basis, said Jeanette Casselano, AAA spokesperson. Part of the price movement is due to a switch to the winter blend of gasoline, which has about 1.7% less energy than summer blend so it can evaporate more quickly at lower temperatures.

"Gas prices are getting cheaper by the day," Casselano said. "Pump prices may not be dropping as fast as motorists would like, but with the switchover to winter-blend gasoline, consumer demand beginning to slow and Gulf Coast refineries getting closer to normal operations, consumers can expect gas prices to continue to be less expensive through October."

The largest price declines came in Midwest and Central states such as Indiana (12 cents), Michigan (12 cents), Kentucky (11 cents) and Ohio (10 cents).

Prices in South and Southeast states remain elevated due to Hurricane Harvey. Gasoline prices are at least 30 cents more expensive than a month ago in Georgia (44 cents), South Carolina (39 cents), Alabama (37 cents), Florida (36 cents), Mississippi (32 cents) and Texas (31 cents), according to AAA.

Meanwhile, the average price of diesel fell three-tenths of a cent to $2.788 for the week. The national average price is now 40.6 cents higher than a year ago.