The refiners, with a straight face, claim that gasoline prices are higher in the winter because they need to reformulate the gasoline for the colder weather...
...in a state where the average lows in December hover between 50° and 60° and the average highs in August are 80° to 90°.
California requires a unique California Air Resources Board (CARB) gasoline with stricter chemical and emissions standards, so refineries must produce and handle it differently than standard U.S. gasoline.