The Washington metropolitan area added 83,100 jobs in the one-year period ending in July —the strongest showing in more than a decade—even as unemployment increased in the District proper, according to data reported Friday by the Bureau of Labor Statistics.

The unemployment rate for the District rose by three-10ths of a percentage point to 6.4 percent during the month. Unemployment in Maryland dropped by a 10th of a percentage point to 4 percent and Virginia’s rate edged up by a 10th of a percentage point to 3.8 percent.

The rise in unemployment at a time of healthy job growth is often a sign that more people are resuming job searches after removing themselves from the workforce. People not actively looking for work go uncounted as part of the unemployed.

The District, Maryland and Virginia each saw the size of their labor forces grow over the past year.

Some economists cautioned the totals could be revised later as the bureau collects more information about employment. A year ago, for instance, a reported spike of more than 94,000 jobs was ultimately lowered to 75,900.

Even if the job growth holds, some economists worry about the types of jobs being added. Friday’s jobs report included only 16,000 jobs in the professional and business services category that includes the region’s government contractors, lawyers and technology workers—sectors that typically command higher salaries. The July numbers were one of the weakest showings in that category in recent memory, and almost all of those jobs were added in Northern Virginia.

Downtown, the job growth was primarily in the leisure and hospitality sector, which includes positions in bars, restaurants and entertainment venues.

Such jobs are a hallmark of city’s post-recession reinvention, in which an influx of young workers are fueling a gentrification boom that in many ways is reshaping the character of the city.

Economists say these jobs tend not to pay as well as the government-centric work that once dominated local job reports. Hospitality jobs, for instance, generally don’t pay as well, and are generally less secure, than professional work. Also, their dependence on consumer spending means they could be jettisoned if the economy takes a turn.

“The short-term economy looks better than we had forecast for the year; we’re doing well,” said Stephen Fuller, an economist with George Mason University. “But in the long term this isn’t sustainable.”