Gas prices are higher in half of the U.S. states this week, including Rhode Island, where a three-cent jump is the first increase since early May, according to AAA Northeast.

Higher crude oil prices, robust demand and shrinking supply, plus the closure of a major northeast refinery in Philadelphia are all factors showing up at the pump.

AAA's July 1 survey of prices in Rhode Island finds self-serve, regular unleaded averaging $2.70 per gallon. Rhode Island's price is one cent lower than the national average for regular unleaded of $2.71. A year ago at this time, the average price in Rhode Island was twenty-two cents higher at $2.92.

"For the more than 41 million motorists hitting the road this week to celebrate the Independence Day holiday, they will find gas prices cheaper than Memorial Day weekend, but more expensive than they've been paying the last few weeks," said Diana Imondi, AAA Northeast Manager of Public Affairs & Traffic Safety. "It's typical to see increases at the pump ahead of the holiday, but we may see prices continue to jump throughout the month due to refinery interruptions on the East Coast, increasing demand and fluctuations in crude oil price."

The range in prices in the latest AAA survey for unleaded regular is 44 cents, from a low of $2.55 to a high of $2.99. AAA advises motorists to shop around for the best prices in their area, and to make sure they and their passengers buckle up - every time.

Find the most up-to-date local gas prices with the AAA Fuel Finder by logging onto AAA.com and clicking on Gas Saving Tips & Tools.

AAA Northeast is a not-for-profit auto club with 66 offices in Rhode Island, Massachusetts, Connecticut, New Jersey, New Hampshire and New York, providing more than 5.7 million local AAA members with travel, insurance, finance, and auto-related services.