The average price of a gallon of self-serve regular was $2.655 as of October 23, said Trilby Lundberg, author of the Lundberg Survey. Since the October 9 survey, the average price per gallon has climbed by 17.82 cents. The current price is 12.3 cents less than the price a year ago.

The retail price of diesel fuel jumped a similar amount in the past two weeks -- 16.75 cents. The price of diesel fuel is $2.817, Lundberg said.

There has been no significant increase in the demand for crude oil, nor large decrease in supplies of crude that can explain almost a $9 per barrel jump in the past two weeks, according to Lundberg. Crude oil now costs $80.50 a barrel.

The average national price for self-serve regular unleaded gasoline was $2.048 a gallon on April 10, up 9.58 cents from March 20, according to the survey of gas stations.

The price was a whopping $1.27 below a year ago levels, when crude oil prices soared.

"The major cause of the rise of nearly a dime in three weeks is seasonal gasoline demand, not only because our consumption rises month by month, but because of the cost of environmental compliance," Survey editor Trilby Lundberg said in an interview.

As the weather warms, refiners are required to limit vapor pressure in order to avoid smog production. This adds to the cost per gallon, she said.