Gas prices finally notch down

NEW YORK (CNNMoney) -- Gasoline prices dipped for a second straight day on Wednesday, providing a reprieve to motorists after a 20-day streak of gains, even though they're expected to rise again.

The nationwide average price for a gallon of regular unleaded gasoline slipped 0.3 cent to $3.533 on Wednesday, reported the motorist group AAA.

The nation's most expensive gas is in Hawaii, with a statewide average price of $4.029, and the cheapest is in Wyoming, with an average of $3.287, according to AAA.

The ongoing march of higher prices started in the last week of February and dragged through much of March. The climb in gas prices resulted from an oil rally fueled by political turmoil in the Middle East and North Africa.

Demand for oil has been stymied by the deadly earthquake and tsunami that has devastated parts of northern Japan, killing 3,771 people and damaging nuclear reactors.

As of Tuesday, oil prices have fallen more than 7% since the 9.0-magnitude earthquake struck last week. But they edged up again on Wednesday, settling up 80 cents per barrel to $97.98.

There's still room to rise for gas prices, as the U.S. shifts into the spring and summer driving season.

"You will see a mixed bag in the next week or so," said Tom Kloza, chief oil analyst at the Oil Price Information Service. "Prices in much of the country will backtrack a bit."

However, this might just be a blip. Kloza believes that gas prices could peak this spring in the range of $3.50 to $3.75 per gallon.

"It's too early but I don't think we've seen the peak yet," he said. "I think that this week is reminding people that there is a downside risk in owning oil or gasoline futures."

Current gas prices are still more than 13% off from their historical peak. Prices reached a record nationwide high of $4.114 on July 17, 2008, according to AAA.