The number of major crimes reported in Washington in the third quarter of this year jumped 29 percent compared with 1979, as the daily average of serious offenses here climbed to more than 200 a day -- the highest in a decade.

The D.C. Police Department's quarterly crime report released yesterday shows, moreover, that the galloping crime rate is affecting every economic level, from low-income residents of public housing projects in far Southeast to affluent families in upper Northwest. The rate for robbery, the street crime most feared by city residents, soared 53 percent, according to police figures. The number of burglaries leaped 41 percent.

"It used to be a time they [criminals] preyed on the better off," said burglary squad Detective Frank Tracy. "Now it's anybody. They are hitting anywhere they can. Nobody's exempt," he added, noting that even the home that D.C. Police Chief Burtell M. Jackson shares with his mother was burglarized recently.

Police officials blamed the increase on a number of factors, including unemployment, increased availability of drugs on the streets, reduction in the police force and low police morale -- all the same reasons they have given since reported crime began increasing significantly here three years ago.

"We are barely . . . holding our own," said Larry Melton, vice president of the International Brotherhood of Police Officers Local 442. "The morale is down."

Melton said morale "is rock-bottom" because the force has been reduced to 3,600 officers with plans for further reductions and the officers have not received an adequate pay raise. "We don't have the man-power to handle it [the city's crime]," he said. "The guys right now feel the administrations of the city and the police department don't really care about them. What's the purpose of me busting my rear end?"

The District is facing a multimillion dollar citywide budget deficit that has led Mayor Marion Barry to cut the budget of individual government agencies, including the police department. A proposed layoff of 204 uniformed officers last summer was averted, but still the department has to contend with a hiring freeze coupled with large-scale retirements.

A high-ranking police official said yesterday the department has had difficulty recruiting a class of 25 persons who would be available to join the force when the city's hiring freeze is lifted. For the past month, officials have been contacting 410 persons who passed the department's entrance examination a year ago to determine if they are still interested in joining the force. Many now have other jobs, while others are unwilling to be kept in limbo until the freeze is lifted. Still others complain that the starting salary of $15,570 is not enough to meet the cost of living in the District since they are required to live in the city.

According to the third-quarter figures released yesterday, major reported crimes -- murder, rape, robbery, aggravated assault, burglary, larceny and auto theft -- increased from 14,236 last year to 18,308 this year.

The numbers of murders jumped from 42 to 57, a 36 percent increase over the third quarter a year ago. Robberies increased from 1,587 to 2,431 and burglaries from 3,338 to 4,722.

Larcenies were up 21 percent, from 7,288 to 8,811, and auto thefts rose from 976 to 1,121, an increase of 15 percent, according to those figures. Aggravated assaults jumped 21 percent, from 862 to 1,044. Rapes, the only major crime to show a decline in the third quarter, decreased 15 percent, from 143 to 122.

The daily average of major reported crimes for the month of October continued at more than 200, the same as August and September, according to police figures.

While this average is the highest in a decade, it is still below the all-time high in November 1969, when the daily average reached 265. The preceding year, Richard Nixon, campaigning for the presidency, had labeled Washington the "crime capital of the nation."

Chief Jefferson has said he does not think the city's crime rate is as alarming as it was in the late 1960s. However, Melton, the police union leaders, said that if the reduction in the force continues, "we will lose the streets to the criminals like we did 10 years ago. The guys right now are praying that now that we have a new president and a conservative Senate, maybe someone will take an interest in the upsurge in crime and increase the force, instead of reduce it."