Washington area gasoline prices, after dropping steadily for months, have jumped 10.1 cents a gallon since mid-March, according to a survey released yesterday by the American Automobile Association.

The average price for all grades of gasoline dispensed from self-service and full-service pumps is now $1.353 a gallon, compared with $1.252 a gallon on March 16, the survey showed.

With this latest increase, motorists are paying nearly twice as much for gasoline as they paid five years ago. The average price for Washington area gasoline on May 18, 1978, was 68.1 cents a gallon, compared with today's average of $1.353.

"Coming after the decreases in OPEC oil prices, this 10.1 cent increase in gas prices boggles our minds," said Tom Crosby, an AAA representative.

Half of the 10.1-cent jump is due to the nickel per gallon federal tax increase that went into effect April 1, industry officials said. They said the other half primarily reflects higher wholesale prices that dealers are paying their suppliers and passing on to motorists.

Oil company spokesmen defended their wholesale price increases, saying that refiners lost money in the first quarter of 1983 and now must start earning profits or risk going out of business.

"You reach a point where you have to raise the price," said Jim Fair, a public relations official for Amoco, which has raised Washington area wholesale prices about six cents a gallon since April 1.

Other companies have made similar wholesale price increases. Exxon, for example, has raised its wholesale prices to Washington dealers by 5.8 cents a gallon since March 16, a spokesman said.

The survey of 119 stations, representing 845 gasoline pumps, by the Potomac Division of AAA represents a dramatic reversal of the pattern of falling pump prices that had prevailed here and in other parts of the nation. On April 3, 1981, for example, Washington's average price for gasoline was $1.454 a gallon. By the spring of 1982, it had fallen 15 cents a gallon. Summer increases raised the price 5 to 8 cents a gallon. But since Aug. 23, 1982, when the average was $1.380 a gallon, the price has gone down steadily, finally bottoming out at $1.252 a gallon on March 16.

Now the average price has risen again, making driving more expensive just as the travel season begins. Filling a car with 15 gallons of gasoline for the Memorial Day Weekend, for example, will cost an average of $1.52 more than it did over the Easter holidays.

The average price per gallon in suburban Maryland remains the lowest of the three jurisdictions, according to the survey. Maryland's average price for a gallon of gasoline, counting all grades and both self and full service pumps, is $1.334. The District of Columbia follows, with $1.361, and Virginia is the most expensive at $1.375.

The survey also uncovered these trends:

* Dollar-a-gallon gasoline is gone. Two months ago, when AAA checked prices, 32 percent of the stations surveyed charged less than $1 a gallon for regular leaded gasoline. But none of those stations had gasoline for that price in the new survey. And only 12.6 percent of them were charging less than $1.10 a gallon.

* Self-service customers have been hit hardest by this round of increases. Areawide full-service gasoline prices increased an average 8.3 cents a gallon, while self-serve prices went up an average 10.2 cents a gallon.

* Motorists still can save money by shopping around for the best buy, pumping their own gasoline and paying cash. Premium unleaded gasoline, for example, ranged in price at full-service pumps from a low of $1.319 a gallon to a high of $1.799--a difference of 48 cents a gallon. Self-service gasoline in the survey cost an average of 21.4 cents a gallon less than full-service gasoline. And cash discounts offered by stations surveyed averaged 5.48 cents a gallon for self-service gasoline and 4.2 cents a gallon for full-service gasoline.

Vic Rasheed, executive director of the Service Station Dealers Association, blasted the oil companies for raising wholesale prices to stations.

"There is nothing to justify increases in wholesale prices at this time; crude oil prices aren't going up--they aren't even stabilizing," he said.

Rasheed said the companies used the April 1 federal tax increase to "piggyback their wholesale price increases . . . so people would think all of the increase was based on the federal tax." He said the increases were continuing because "we are approaching the driving season" and the oil companies "figured this was an opportunity to go up again."

Diesel fuel also has gone up in price--but not nearly as much as gasoline, AAA said. Area prices for diesel currently average $1.274 a gallon, an increase of 1.8 cents a gallon since mid-March. But, industry officials noted, it is just as traditional for the price of diesel fuel, which is essentially the same as heating oil, to go down at the end of the heating season as it is for gasoline prices to go up at the beginning of the travel season.