WASHINGTON — More than 90 percent of the nation's largest metropolitan areas saw their unemployment rates climb in June from the previous month.

Some of the biggest increases hit college towns, where the annual summertime exodus of students causes bars, restaurants and other businesses to cut staff. The Detroit area, hit hard by manufacturing layoffs tied to the beleaguered auto industry, also got stung in June.

Unemployment rates rose from May to June in 348 of more than 370 metro areas, according to an analysis of Labor Department data released Wednesday.

The figures aren't adjusted to account for seasonal trends, such as lifeguards hired during summer or retail clerks let go after the holiday shopping season. So they tend to be volatile from month to month.

The Labor Department does not provide seasonally adjusted metro area unemployment data. It does adjust the national unemployment rate for seasonal factors. The U.S. jobless rate, which hit 9.5 percent in June, is expected to rise to 9.7 percent when the department reports the July rate next week.

Tuscaloosa, Ala., home to the University of Alabama, suffered the biggest monthly increase in unemployment from May to June. Its jobless rate jumped to 12.5 percent in June, up 3.8 percentage points.

Michigan's metro area of Detroit-Warren-Livonia posted the second-biggest monthly gain. The unemployment rate there climbed to 17.1 percent, a gain of 2.2 percentage points.

Pocatello, site of Idaho State University, saw the third-biggest monthly rise. The metro area's unemployment rate rose to 7.8 percent in June, up 2 percentage points from May.

Next were Laredo, Texas, home of Laredo Community College, with a June jobless rate of 9.4 percent; Lafayette, Ind., which includes Purdue University, with a rate of 10.5 percent; and McAllen-Edinburg-Mission, Texas, at 11.1 percent. Each saw its unemployment rate rise 1.7 percentage points from May.