The average price of a gallon of self-serve regular unleaded gasoline rose one-tenth of a cent to $2.265 -- 7.4 cents more than last week and 24.6 cents more than a month ago, but 88.3 cents less than at this time last year and $2.361 less than the record high of $4.626 set on June 21.
The average price has risen 18.2 cents over the past 15 days, including a half-cent Monday.
The Orange County average price also rose for the 15th consecutive day on Tuesday. The increase of two-tenths of a cent to $2.257 was the second-smallest of the current streak, behind only Monday's one-tenth of a cent rise.
The Orange County average for unleaded regular has risen 18.9 cents over the past 15 days. It is 7.7 cents more than last week and 25.2 cents more than a month ago, but 82.2 cents less than at this time last year and $2.341 less than the record high of $4.598 set on June 19.
The increases are the result of reduced supply, caused by the combination of lower production at the state's refineries and the switch from the winter blend of gasoline to the summer blend, according to Jeffrey Spring of the Automobile Club of Southern California.
The national average price of a gallon of unleaded self-serve regular gasoline declined a half-cent to $1.96 today, a day after it ended a 19-day streak of rising prices by decreasing by one-tenth of a cent. The average price is 3.2 cents more than a week ago and 12.1 cents more than last month, but $1.054 less than this time last year and $2.154 less than the record high of $4.114 set July 17.
California's gasoline prices are typically higher than the national average and among the highest in the nation because of taxes and a state law mandating a special blend of fuel to reduce polluting emissions.