Industry analyst Trilby Lundberg said Sunday a gallon of regular now costs $3.29 on average. Gas is 30 cents a gallon cheaper than this time last year
Lundberg says the price has dropped more than a nickel per gallon in the past month, but it's unlikely to fall further unless crude oil prices plunge.
Diesel prices rose in the past two weeks by six cents to $3.95 per gallon.
Of the cities surveyed in the lower 48 states, Billings, Mont., has the lowest price at $2.99 a gallon and San Diego has the highest price at $3.63.
Within California, Sacramento has the lowest price per gallon at $3.34.