WASHINGTON, D.C. --- For the second week in a row, retail diesel prices tumbled in all regions of the country, according to a weekly report from the Energy Department.

The U.S. average price for diesel dropped to $4.603 per gallon, a decline of 11.5 cents, the department's Energy Information Administration (EIA) reported July 30.

Nonetheless, the price was $1.717 higher than a year ago. The average price on the East Coast fell 10.9 cents to $4.664 per gallon. The price in the Midwest remained the lowest of any region at $4.518 per gallon following a plunge of 13.1 cents. The average price in the Gulf Coast also plummeted 13.1 cents, to $4.57 per gallon.

In the Rocky Mountains, the price of $4.657 per gallon reflects a fall of 5.7 cents, the smallest decline of any region. On the West Coast, the average price decreased 7.9 cents to $4.766 cents per gallon. In California, the average price was $4.869 per gallon, a drop of 9.5 cents.