Jobless rates dropped in most metropolitan areas in September, and among areas with populations of one million or more they fell the most in Las Vegas, federal data released on Wednesday showed.

In 249 out of 372 metropolitan areas, unemployment rates were lower than a year earlier. They were higher in 102 areas and stayed the same in 21, according to the U.S. Labor Department. Metropolitan areas tend to include cities along with their surrounding suburbs.

Las Vegas continued to have the highest unemployment rate out of the 49 areas with populations of one million or more, at 13.6 percent, but that was two percentage points lower than in September 2010.

The bursting of the housing bubble more than three years ago was particularly threatening to southwestern states such as Nevada, California and Arizona that had relied on building and new homes sales for economic growth.

Las Vegas was especially hard hit, as was the large nearby area over the California border known as the Inland Empire. That metropolitan area, which includes Riverside, San Bernardino and Ontario, had the second highest unemployment rate of all large areas -- 13.4 percent in September.

The lowest jobless rate among large areas was recorded in Oklahoma City at 5.5 percent. Altogether 36 of the biggest metropolitan areas registered unemployment rate drops over the year.

Of all metropolitan areas, El Centro, California, and Yuma, Arizona, continued to hold the highest unemployment rates. El Centro's rate was 29.6 percent in September and Yuma's was 15 percent. Five other areas had rates of at least 15 percent, all located in California, the Labor Department said.

The federal government does not seasonally adjust unemployment rates at the metropolitan level, a process it typically follows for the national unemployment rate to smooth out the numbers and make them more comparable over time.

Without seasonal adjustment, the U.S. unemployment rate was 8.8 percent in September, compared to 9.2 percent a year earlier, the Labor Department said. It added that 84 metropolitan areas had jobless rates of at least 10 percent and 95 areas has rates below 7 percent in September.

Jobs have become the number one U.S. political issue as the country struggles to recover from the 2007-09 recession, the deepest and longest U.S. economic downturn since the Great Depression.

On Friday, the Labor Department will release the national employment report for October and analysts polled by Reuters expect it so show the seasonally adjusted jobless rate was 9.1 percent.