By G. SCOTT THOMAS
sthomas@bizjournals.com | 716-541-1618

Washington is the strongest job market in the United States.

The nation's capital is No. 1 in this month's On Numbers rankings of employment vitality, up from third place a month ago.

Business First analyzes private-sector job data and unemployment rates on a monthly basis, generating overall scores for America's 100 biggest metros. Fifty percent of each area's score is based on its annual private-sector growth rates during the past five years, 30 percent on its jobless rates over the past 12 months, and 20 percent on its raw changes in private-sector employment in half a decade.

Washington moved up from third place a month ago to first place in our current standings, thanks to its strong job growth during the past year (2.8 percent) and remarkably low unemployment rate (5.9 percent).

Rounding out the current top five are Dallas-Fort Worth, Houston, Pittsburgh and Austin. (The three leaders a month ago were Houston, Dallas-Fort Worth and Washington, in that order.)

Pittsburgh is undoubtedly the biggest surprise at the top of the standings, but its high position is merited. The Pittsburgh area has added 23,600 private-sector jobs in the past year. And its unemployment rate of 7.9 percent is a full point below the corresponding national rate for February, 8.9 percent.

Sacramento is the nation's weakest job market, changing places with Las Vegas, which now clings to 99th place in the standings. Both areas have unemployment rates above 12 percent, and each has lost at least 100,000 private-sector jobs since 2006.

The latest On Numbers employment rankings - and all databases mentioned in this story - can be accessed at http://tinyurl.com/on-numbers.

Metropolitan areas received substantial publicity when the U.S. Census Bureau recently issued its 2010 census results.

Their little cousins, known as micropolitan areas, were virtually ignored.

Micros are small-scale versions of metros. Both consist of central cities and their surrounding territories. The difference is in size. The city at the core of a metropolitan area must have at least 50,000 residents, while a micropolitan hub ranges from 10,000 to 49,999.

Total populations also vary dramatically. Metros often have more than a million residents, ranging as large as 20 million in the New York City area. But no micro is bigger than 200,000, encompassing its central city, suburbs and nearby rural communities.

That's not to say that micropolitan areas aren't popular. More than 70 percent of the nation's 576 micros - 411, to be exact - gained population between 2000 and 2010.

Some of the increases were truly spectacular. The Villages, a popular retirement area northwest of Orlando, added 40,075 people in 10 years, a 75 percent jump. The coastal resort of Hilton Head Island-Beaufort, S.C., shot up by 32 percent. Daphne-Fairhope-Foley, which hugs the eastern shore of Alabama's Mobile Bay, grew by 30 percent.

Micropolitan areas, despite their small size, can be significant markets. The total population of America's 576 micros was 30.9 million last year, up 5.9 percent from 29.2 million a decade earlier.

Especially appealing are those areas that combine size and rapid growth. A dozen micros coupled 2010 populations of more than 100,000, with growth rates higher than 15 percent.

There were no losers in the 2010 census, though some parts of the country won more than others.

All 13 sections of the United States gained population between 2000 and 2010, but the growth rates varied widely, according to our breakdown of new U.S. Census Bureau figures.

Texas - one of four states large enough to be considered a section by itself - set the national pace by adding 4.3 million residents in 10 years, a jump of 20.6 percent.

The Eastern Great Lakes - consisting of Indiana, Michigan and Ohio - brought up the rear with an anemic growth rate of 1.9 percent.