The average price of a gallon of self-serve regular gasoline in San Diego County rose four-tenths of a cent Friday to $4.779, its highest amount since May 28.

The average price is 3.5 cents more than one week ago, 23.3 cents more than one month ago and 8.8 cents more than one year ago, according to figures from the AAA and the Oil Price Information Service. It has dropped $1.655 since rising to a record $6.434 on Oct. 5, 2022.

“According to Oil Price Information Service, the Phillips 66 refinery in Wilmington and Carson has begun permanently winding down operations there after announcing it would shut down by the end of this year,” Automobile Club of Southern California spokesman Doug Shupe said Thursday.

“OPIS also reports that yesterday’s Energy Information Administration data shows West Coast refinery utilization rates are at a four-month low point. This lower level of activity is common at this time of year as demand drops and refineries begin the process of switching to produce winter blend gasoline that can be sold in pumps starting Nov. 1.”

The national average price decreased four-tenths of a cent to $3.199. It is 1.1 cents more than one week ago and 6.9 cents more than one month ago, but 2.5 cents less than one year ago. The national average price has dropped $1.817 since rising to a record $5.016 on June 14, 2022.