The unemployment rate for District of Columbia residents in June was 8.3 percent of the work force, adjusted for seasonal variations, the D.C. Labor Department reported yesterday. That was 0.1 percent higher than the same month of 1978.

For residents of the metropolitan area as a whole, including the District, the adjusted jobless rate in June was 4.6 percent, a figure 0.1 percent lower than the same month of 1978. There was no breakdown of race or age.

These figures compared with a national unemployment rate of 5.6 percent in June.

Without the seasonal adjustment the jobless rate in the District in June was 9.1 percent, and for the region as a whole it was 5.1 percent.

In seeming contradiction, the slight rise in the unemployment rate among District residents in June of this year was accompanied by a slight decline in the actual number of people without jobs.

This resulted from a shift in job patterns, the Labor Department reported. The numbnr of District residents in the work force -- those with jobs or those actively seeking jobs -- declined by 11,500 over the year's time. Total employment among District residents declined by 10,900. With figures rounded off, this meant that 500 fewer people in the smaller work force were unemployed.

Rufus Daniels, labor economist for the Labor Department, said he had no explanation for the drop in the work force other than "the downward trend in the District population," especially among those in the younger age group entering the job market.

Between May and June the District jobless rate rose from 8.1 percent to 9.1 percent (without making seasonal adjustments), reflecting a normal annual trend as students seek summer jobs or graduates seek permanent employment.

Total employment among District residents in June was 294,600. For the region as a whole, it was 1.5 million.