WASHINGTON, D.C. --- For the first time in three months, the U.S. average retail price for regular gasoline did not increase, according to a weekly report released by the Energy Department on Wednesday, June 25.

Instead, the price dipped slightly, but only by three-tenths of a cent to $4.079 per gallon. Regionally, price changes were mixed, with small increases in the Rocky Mountain and West Coast regions and slight drops in the other regions, according to the Energy Department's Energy Information Administration (EIA).

The average price for the East Coast slipped by half a cent to $4.047 per gallon. The Midwest had the smallest change with the price falling by only a tenth of a cent to $3.996 per gallon. The Gulf Coast price dropped the most of any region, down 1.8 cents to $3.919 per gallon. The Rocky Mountain regional price topped $4 for the first time, rising 0.8 cent to $4.002 per gallon. The price on the West Coast also increased by 0.8 cent to $4.46 per gallon. Contrary to the regional West Coast price, the average in California fell slightly, dropping three-tenths of a cent to $4.585 per gallon.

Meanwhile, retail diesel prices declined 4.4 cents to $4.648 per gallon, recording the largest weekly decrease since Jan. 21, the EIA reported. Diesel prices fell in all regions of the country but dropped the most on the Gulf Coast.

The average diesel price on the East Coast fell 4.1 cents to $4.711 per gallon. In the Midwest, the price of diesel dipped 4.4 cents to remain the lowest of any region at $4.574 per gallon. The average price in the Gulf Coast was 5.4 cents less at $4.602 per gallon.

The price of diesel in the Rocky Mountains fell 3.3 cents to $4.652 per gallon. On the West Coast, the average diesel price dipped 3.6 cents to $4.816 per gallon. In California, the average diesel price went down for the third week in a row, falling 4.7 cents to $4.922 per gallon. Despite a drop of 10.5 cents from the all-time high of $5.027 per gallon set in May, the price in California was 27.4 cents above the national average.