RIVERSIDE, Calif. -

Average retail gasoline prices in Riverside have risen 2.6 cents per gallon in the past week, averaging $4.05 per gallon Sunday, according to GasBuddy's daily survey of 481 gas outlets in Riverside. This compares with the national average that has increased 3.2 cents per gallon in the last week to $3.68/g, according to gasoline price website GasBuddy.com. 

Including the change in gas prices in Riverside during the past week, prices yesterday were 31.0 cents per gallon higher than the same day one year ago and are 0.6 cents per gallon lower than a month ago. The national average has increased 9.9 cents per gallon during the last month and stands 19.0 cents per gallon higher than this day one year ago. 

"The national average has seen the upward trend continuing, with average prices climbing across an abundance of the U.S.," said GasBuddy.com Senior Petroleum Analyst Patrick DeHaan. "The price of WTI oil continues to rise to levels not seen in quite some time, and that may continue, at least for the time being, to put more upward pressure on gasoline prices. While the worst may be behind us, I do believe the week ahead will likely feature another rise in the national average," DeHaan said.