NEW YORK (CNNMoney.com) -- Retail gas prices hit record highs for the sixth straight day, auto group AAA's Web site showed Tuesday.

The latest reading from AAA showed that the nationwide average for a gallon of regular unleaded hit $3.732, up from $3.718 the previous day.

Gas prices have now increased for seven straight days. The climb comes ahead of the Memorial Day holiday and start of the summer driving season.

The AAA national average shows gas prices up nearly 11% over the past month and up 21% from year-ago levels.

The surge in gas prices comes on the back of climbing crude prices, which have doubled in the last 12 months.