A refinery in California will close longer than expected, causing prices to soar.
Gas prices on the West Coast spike 25-cents over the last week. Oregon's average is $3.92 and Washington's average is $3.91.
The AAA reports that the sharp increase is due to the Exxon-Mobile refinery in California closing for maintenance longer than expected. Gasoline supplies are tight in California, so unplanned disruptions in production cause dramatic price increases. If a second refinery were to go down at the same time prices would spike even higher.
Other factors causing prices across the country to rise include the improving economy and the rising price of crude oil.
Diesel in Oregon increased 7-cents to $3.99 a gallon.