NEW YORK (CNNMoney.com) -- Retail gas prices have risen to an all-time high for the third straight day, according to a survey from motorist group AAA.

The national average price for a gallon of regular gas rose five-tenths of a cent overnight to $4.092, the daily survey showed Wednesday. That tops the previous day's record of $4.087 a gallon.

Gas prices are now about 3% higher than last month and 38.5% higher than year-ago levels.

Alaska has the highest gas prices. Drivers in the state pay an average of $4.649 a gallon for regular gas. California has the second-highest gas prices, averaging $4.578, followed by Hawaii at $4.446.

The lowest gas prices in the nation can be found in Oklahoma. The state has an average price of $3.878 a gallon.

The survey also showed that the national average price for diesel fuel rose to $4.767 from $4.762 the day before. Diesel prices are highest in Hawaii, where the average price is a whopping $5.347 a gallon.

Rising gas prices contributed to a sharp decline in June auto sales. Unadjusted sales fell 18%, far worse than the 12% decline forecast by sales tracker Edmunds.com,

Despite the rising popularity of fuel-efficient cars, sales of fuel sippers fell in June, as many automakers were unable to keep up with rising demand for small cars.