California’s average state price for one gallon of gasoline has risen to $6. This makes fuel in California the most costly across the U.S.

AAA reports that the average pump cost in California reached $6.021/gallon Tuesday. The prices are now up 31 cents and $1.89 over last year.

California is the least expensive state, however gas prices across the nation are rising.

On Tuesday, the national average reached a new record of $4.523. Every state has a median value greater than $4.

This sharp rise is due in part to an increase in oil prices which accounts for more than half the final price of gasoline.

AAA spokesperson Andrew Gross said that “the high cost oil, which is the main ingredient in gasoline,” was driving high pump prices for consumers Monday.

He added that “Even the annual seasonal gasoline demand dip between spring break and Memorial Day which would normally lead to lower prices is not having any effect this year.”

Oil isn’t the only thing that affects gas prices. A lack of refining capability is also a factor.

Oil is transformed into products such as gas by refining companies. The rapid rise in prices is due to increased demand as the economy recovers.

Prices for retail diesel are also rising. The national average price per gallon of diesel hit a new record at $5.573 Tuesday. Over the past year, prices are up by $2.40.