This map, prepared by the Iowa Data Center, shows the new population estimates for each county and the percent change since the 2013 estimate. Click to see full size. (Iowa Data Center/used with permission)
By Bob Eschliman
Editor
Last week, the U.S. Census Bureau released its latest county population estimates, effective July 1 of last year.
The new estimate found Iowa’s population has grown to 3,107,145. In 2010, the official Census declared the state’s population as 3,046,355. The data has been compiled and released by the Iowa Data Center.
According to the new numbers, 30 Iowa counties had population increases of at least 0.1 percent from July 1, 2013, to June 30, 2014. During that same period, 61 saw population loss of at least 0.1 percent.
Largest Counties by Population
- Polk County – 459,862
- Linn County – 217,751
- Scott County – 171,387
- Johnson County – 142,287
- Black Hawk County – 132, 897
- Woodbury County – 102,271
- Dubuque County – 96,370
- Story County – 94,073
- Pottawattamie County – 93,128
- Dallas County – 77,400
Smallest Counties by Population
- Adams County – 3,875
- Ringgold County – 5,051
- Audubon County – 5,794
- Taylor County – 6,143
- Osceola County – 6,218
- Wayne County – 6,395
- Fremont County – 7,022
- Ida County – 7,042
- Pocahontas County – 7,138
- Adair County – 7,454
The fastest-growing county in Iowa continues to be Dallas County. It’s estimated annual growth was 3.6 percent in 2014. Formerly one of the fastest-growing counties in the U.S., it has fallen behind oil-rich counties in North Dakota and Texas.
Also among the fastest-growing counties in Iowa are Johnson, Polk, Warren, and Worth. Each county is estimated to have grown its population by at least 1 percent from 2013 to 2014.
Fastest Growing Counties by Percentage
- Dallas County – 3.6%
- Johnson County – 1.8%
- Polk County – 1.8%
- Warren County – 1.2%
- Worth County – 1.1%
- Madison County – 0.9%
- Linn County – 0.8%
- Story County – 0.7%
- Bremer County – 0.6%
- Buchanan County – 0.5%
- Dubuque County – 0.5%
- Greene County – 0.5%
- Grundy County – 0.5%
- Marion County – 0.5%
- Scott County – 0.5%
- Sioux County – 0.5%
The fastest-shrinking county in Iowa, according to the Census Bureau, was Audubon County, which was estimated to have lost 1.5 percent of its population from 2013 to 2014. Ida, Hamilton, Louisa, Monona, Cass, and Crawford counties each lost at least 1 percent of its population, according to the new estimates.
Fastest Shrinking Counties by Percentage
- Auduon County – 1.5%
- Ida County – 1.4%
- Hamilton County – 1.3%
- Louisa County – 1.2%
- Monona County – 1.2%
- Cass County – 1.1%
- Crawford County – 1.1%
- Franklin County – 0.9%
- Wright County – 0.9%
- Fayette County – 0.8%
- Harrison County – 0.8%
- Keokuk County – 0.8%
- Palo Alto County – 0.8%
Coming as probably no surprise to anyone, the Third Congressional District saw the most population gain, growing to 800,934. As originally drawn based on the 2010 Census, the district had a population of 761,612.
Largest Counties by Population – Third Congressional District
TOTAL POPULATION: 800,934
- Polk County – 459,862
- Pottawattamie County – 93,128
- Dallas County – 77,400
- Warren County – 47,956
- Page County – 15,496
The Fourth District has shown a population loss. It’s estimated 2014 population was 759,458, while its official population in 2010 was 761,571.
Largest Counties by Population – Fourth Congressional District
TOTAL POPULATION: 759,458
- Woodbury County – 102,271
- Story County – 94,073
- Cerro Gordo County – 43,254
- Webster County – 36,955
- Sioux County – 34,681
The First District has grown in population by about 8,300 over the same period. Meanwhile, the Second District has grown by about 15,200.
Largest Counties by Population – First Congressional District
TOTAL POPULATION: 769,863
- Linn County – 217,751
- Black Hawk County – 132,897
- Dubuque County – 96,370
- Marshall County – 40,866
- Benton County – 25,680
Largest Counties by Population – Second Congressional District
TOTAL POPULATION: 776,890
- Scott County – 171,387
- Johnson County – 142,287
- Clinton County – 48,051
- Muscatine County – 42,903
- Des Moines County – 40,255
You can be assured this information will be useful to the presidential campaigns as they begin to formulate their strategies to win the first-in-the-nation Iowa Caucus next year. According to the latest data from the Office of Secretary of State, “no party” voters now make up the largest percentage of active Iowa voters.
Follow Us