Motorists in California, the state with the most expensive gasoline, could see pump prices that begin with a 4 again as oil markets rally.

Gasoline, which is currently averaging $3.30 a gallon in California, may reach $4 by Memorial Day, the traditional start of the demand-heavy summer driving season, according to Patrick DeHaan, head of petroleum analysis at Boston-based GasBuddy, which monitors fuel prices across the U.S. It would be the first time the state has seen $4 gasoline since July 2014.