After increasing the prior week, the national average price of gasoline posted a modest decline last week, with prices dropping in a majority of states, according to price-tracking service GasBuddy.

The national average fell 2.6 cents per gallon in the past week, averaging $3.76 on Monday, GasBuddy reported. That’s 14.3 cents per gallon less than a month ago but 36.3 cents more than a year ago.

A decline also was seen in the Pittsburgh area, where the average came down 1.5 cents per gallon to $3.98 on Monday, according to GasBuddy’s survey of 731 stations in the region. That’s 0.7 cents less than a month ago but 43.3 cents more than a year ago.

Prices in the Pittsburgh region range from $3.70 per gallon up to $4.39, a difference of 69 cents per gallon, according to GasBuddy.

“The decline has been partly driven by Great Lakes states, where prices fell by 15 to 25 cents per gallon due to an improvement in the refining situation, and also oil prices, which fell back under $90 per barrel last week,” said Patrick De Haan, head of petroleum analysis at GasBuddy.

“With oil prices remaining volatile, the outlook is murky, but I’m hopeful in the lead up to Thanksgiving we’ll see prices declining in more states, while others may not be quite as lucky,” he said. “Regardless, we’ll still be seeing the most expensive Thanksgiving Day prices on record.”

AAA spokesperson Andrew Gross said there are now about 13 states that have some stations selling gas below $3 per gallon.

“More gas stations could follow, which may be a big help with road-trip budgeting as Thanksgiving approaches,” Gross said.

AAA was reporting Pennsylvania’s statewide average at $4.09 on Monday. County averages range from about $3.93 per gallon to $4.23. County averages are lowest mainly in the southwest corner of the state.

County averages in the Pittsburgh area:

• Allegheny: $4

• Armstrong: $3.99

• Beaver: $3.98

• Butler: $3.96

• Washington: $4.02

• Westmoreland: $4

Neighboring areas and their current gas prices as reported by GasBuddy:

• Akron: $3.63, down 19.6 cents from last week.

• Cleveland: $3.70, down 17.2 cents from last week.

• West Virginia: $3.58, unchanged from last week.

The national average price of diesel has increased 2.3 cents in the past week and now stands at $5.34 per gallon, according to GasBuddy.