Unemployment among District of Columbia residents continued to increase in February, rising from 8.2 percent to 8.5 percent, with 2,000 more Washingtonians unemployed during that month than during the same period a year ago, according to figures released yesterday by the city.

The increases maintains the city's unemployment rate at a significantly higher level than that for the country as a whole. The national rate stood at 7.3 percent for both February and March.

But while unemployment in the District increased, comparable figures for the Washington metropolitan area declined slightly in February, from 4.6 to 4.5 percent. The figures appeared to mean that while the region's economy remains relatively healthy, District residents are not getting the available jobs.

Ironically, there were nearly 2,000 more jobs in the District this February compared with February of last year, while over the same period the D.C. labor force has decreased by nearly 11,000. Thus, unemployment increased even while a smaller pool of potential workers was seeking employment from a larger pool of available jobs, apparently indicating that the jobs were being filled by metropolitan area residents who do not live in the District.

The February increase follows a sharp jump in unemployment for D.C. residents in January, when the seasonally adjusted jobless rate was found to be a full percentage point above the January 1980 level. The February figures announced yesterday continue to show the one-percent gap: in February of 1980, D.C. unemployment was 7.5 percent.

Officials said the figures seem to point to construction, retail sales and government as the areas most responsible for the unemployment increase.

According to the city's figures, there were 25,700 unemployed people in the District in February, up from 25,100 in January and 23,600 in February 1980.

The city does not keep figures on which places of employment are responsible for these changes, according to Department of Employment Services analyst Lawrence Thurston. Instead it takes clues from separate figures that show the number of jobs currently available in the various industries.

The figures show that the city lost 200 construction jobs in February, 500 retail trade jobs and 700 federal government jobs. Most other categories remained stable, with some, like the service industry, registering slight increases. The service category, including hotels and restaurants, has been responsible for virtually all the increase in available jobs in the District over the last year.

While the District's labor force has been declining, the labor force in the metropolitan area has increased over the last year by 14,000. About 11,000 of these new job seekers apparently found work, providing for only a statistically insignificant increase in metropolitan unemployment over the past year.

The gap between metropolitan unemployment and the higher District unemployment rate has grown by nearly a full percentage point since last February.