The weekly national average gas price fell about 2 cents to $3.57 for a gallon of regular, the Energy Department's Energy Information Administration reported on Monday, though Hurricane Sandy may affect East Coast refineries enough to push prices higher later.

Read more: ABC News' Hurricane Sandy coverage

Oil prices have fallen before the financial markets closed on Monday due to Hurricane Sandy. Analysts are expecting a drop in demand as drivers stay off the road.

Patrick DeHaan, senior petroleum analyst with gas price tracking website GasBuddy, said the company has seen a major drop in price reports submitted by drivers in areas affected by Sandy. Normally, GasBuddy receives hundreds of thousands of gas price updates from the 50 states, he said.

In Washington, D.C., price reports dropped 55 percent compared to last Monday.

DeHaan said Hurricane Sandy may not affect gasoline prices significantly, "but long term changes will depend on how hard the region is hit."

If refineries in the region restart operations quickly after the storm subsides, he said he expects minimal pricing increases.

"If there are long term outages at refineries, there may be a more pronounced increase," he said.

After Hurricane Irene in August 2011, the national average rose about 8 cents a gallon, according to GasBuddy.

"For Sandy, I'd expect even less of an increase at this point," he said.

Prices may rise 5 to 15 cents a gallon in the Northeast, he said, "but the biggest impact remains to be seen after Sandy moves out."