UPDATE: View our newer map with more recent 2012 data.

Many counties have seen sizable swings in population since the 2010 Census.

Estimated changes in population, shown in the map below, occurred from April 2010 to July 2011. For some counties, recent poulation trends were much different than shifts experienced during the prior decade.

Much of the counties reporting the largest gains are in the southern and western regions of the U.S.

Harris County, Texas, gained an estimated 88,452 residents – the largest raw increase of any county. The county’s birth rate more than tripled its death rate, according to census data. Los Angeles County, Calif., added 70,451 residents – second only to Harris County.

The map below shows the fastest growing counties by percent change. Select and drag to pan the map or click a county to view detailed data.

 
Percent change since 2010 Census
 
 
 
 
 
 
< -1% -0.1 to -1% No Change   < +1% +1 to 3% > +3%

Counties with the largest raw population increase:

County 2011 Estimate 2010-2011 Change Percent change
Harris County, Texas 4,180,894 88,452 2.2
Los Angeles County, California 9,889,056 70,451 0.7
Maricopa County, Arizona 3,880,244 63,127 1.7
Miami-Dade County, Florida 2,554,766 58,331 2.3
Riverside County, California 2,239,620 49,979 2.3
Dallas County, Texas 2,416,014 47,875 2.0
Orange County, California 3,055,745 45,513 1.5
San Diego County, California 3,140,069 44,756 1.4
Bexar County, Texas 1,756,153 41,376 2.4
Tarrant County, Texas 1,849,815 40,776 2.3
Travis County, Texas 1,063,130 38,858 3.8
Hillsborough County, Florida 1,267,775 38,549 3.1
King County, Washington 1,969,722 38,473 2.0
Broward County, Florida 1,780,172 32,106 1.8
San Bernardino County, California 2,065,377 30,167 1.5
Collin County, Texas 812,226 29,885 3.8
Fulton County, Georgia 949,599 29,016 3.2
Wake County, North Carolina 929,780 28,787 3.2
Kings County, New York 2,532,645 27,945 1.1
Santa Clara County, California 1,809,378 27,736 1.6