The price of gasoline at pumps in the Washington area is higher as the Labor Day weekend approaches than at any time in the last 18 months, according to a survey released yesterday by the local division of the American Automobile Association.

The average price of gasoline in this area is $1.396 a gallon, which is 1.6 cents more than at the corresponding time last year, and more than at any time since Feb. 1, 1982, when it was $1.408, the report said.

Last August, the retail price of gasoline here began a decline that reached a level of $1.252 a gallon on March 16, but has been rising since then, the motoring group said after checking 100 service stations in Washington, Maryland and Virginia.

On May 18 the price was $1.353, and it was $1.370 a gallon nine weeks ago, the AAA said.

The 10-cent jump between March and May has been partly attributed by industry officials to the nickel-a-gallon federal tax increase that took effect April 1.

The officials also cited higher wholesale prices that they said dealers were paying suppliers and passing on to motorists.

Yesterday the AAA said the higher prices apparently awaiting Labor Day travelers come at a time when the wholesale price of gasoline paid by service station owners has dropped.

The AAA also attributed to several industry analysts and station owners the view that the increase reflects an effort by the owners, who were squeezed financially in previous months, to restore their profit margins.

However, a spokesman for the service station owners took issue with the AAA's position.

"As far as I know," said William L. Shoemaker, executive director of the owners' group, there has been "no significant drop in wholesale prices over a couple of months."

In addition, he said that because of increases in such costs as rent, "dealer margins are probably less now than at any time of the year."

Speaking for the Greater Washington-Maryland Service Station Association, which he said represents about 1,200 dealers, Shoemaker said that pump prices have been "relatively static since May or June."

In its survey report, the AAA said that "for the first time in recent memory" average gasoline prices were essentially equal in Maryland, Virginia and D.C.

D.C. prices were listed as the area's highest, at $1.397, followed by Maryland and Virginia at $1.396.

The survey said D.C. prices rose by 3.8 cents since July 4, Maryland's by 3.4 cents and Virginia's by 0.9 cents.

The AAA said that on the average motorists can save 21.1 cents per gallon in the Washington area by pumping their own fuel. It said the lowest price for a gallon of gasoline was $1.119, charged at a self-service pump in a station in Montgomery County. The station was not identified.

It said the highest price found in the survey was $1.799 for a gallon of premium unleaded fuel at a full-service station, also unidentified, in Northern Virginia.