SAN FRANCSICO (CBS SF) – Gas prices in San Francisco have fallen nearly five cents per gallon in the past week, continuing a downward trend over the last several weeks.

According to GasBuddy, the average price of regular is at $3.83 a gallon, which is 27 cents lower than it was a month ago, but is 2.6 cents per gallon higher than a year ago.

Meanwhile, in the Oakland area, the average price of regular has dropped 4 cents from last week to $3.81 a gallon. In the South Bay, a gallon of regular costs $3.77 a gallon, down 5.3 cents.

Nationally, the average price of a gallon of regular is $2.65 per gallon, down 19.2 cents from this time last year.

While prices have dropped in the last several weeks, California drivers will likely pay more to fill up next month, with gas taxes set to rise from 41.7 cents to 47.3 cents per gallon. The tax increase, which is expected to raise $50 billion over the next decade, would go towards repairing roads and infrastructure.