(CNN) -- Gas prices have dropped more than 7 cents over the past two weeks, but risen in some regions stricken by Superstorm Sandy, according to a survey published Sunday.
The new national average for regular gasoline is $3.47 -- down more than 36 cents over the past six weeks, the Lundberg Survey found.
"This latest decline comes mostly from weak gasoline demand," said publisher Trilby Lundberg, "both because we are in the lower demand season and have also lost our daylight saving time. Losing that puts a damper on driving."
Sandy's impact in the Northeast lowered demand as well, since many people were stuck at home, unable to drive.
But because there was also "great difficulty getting fuel to the end user point," gas prices went up in some of those same areas, she said.
The highest average price found by the latest survey was $4.18 for New York's Long Island. That average was up 26 cents from two weeks earlier.
Long Island generally has higher prices than the national average due to taxes.
The Lundberg Survey tallies prices at thousands of gas stations nationwide.
Good news should lie ahead for consumers around the country, Lundberg said.
"Pump prices may well drop some more form here -- unless crude oil prices get seriously spooked by Middle East conflict or another geopolitical issue."
The current nationwide average is 9cents above the average a year ago, "whereas most of this year it's been more like 16 cents," Lundberg said.
The city with the lowest average in the latest survey was Memphis, at $3.04.
Here are average prices in some other cities:
San Diego - $3.80
Seattle - $3.49
Las Vegas - $3.57
Denver - $3.35
El Paso - $3.36
St. Louis - $3.14
Boston - $3.69
Atlanta - $3.24
Miami - $3.42