The population growth in Johnson County grew by 12.1% in the past 10 years, according to additional 2020 Census results released on Aug. 12.
Johnson County’s population was 609,863, on April 1, 2020, the designated Census Day. The county had the second highest percentage of growth in Kansas with Pottawatomie County being the fast-growing county at 17.3%. The population of Pottawatomie County was 24,348 in the 2020 Census.
Over the past 50 years, the Johnson County population has almost tripled since the 1970 Census reported 220,073 residents. The increase over the 2010 census was 65,684. This equates to about 6,500 per year, a little slower than growth rate between 2000 to 2010 (451,086 to 544,179) with a difference of 93,093 or about 9,300 annually.
Johnson County had the best self-response rate in the 2020 Census in Kansas with 78.6% of the residents completing the census and surpassing Kansas (68.6%) and national (67%) self-response rates. Back in October 2018, Johnson County became the first Kansas county to proclaim its partnership with the U.S. Census Bureau for the 2020 Census. On April 1, 2019, Johnson County and several partners including cities, chambers of commerce and non-profits launched the Count me in JoCo outreach and education campaign to promote the importance of census participation.
According to the 2020 Census, Sedgwick County has a population of 523,824, up 5.1% from 2010. Johnson County’s population growth (65,684) was more than double what Sedgwick County gained (65,684 vs 25,459) since 2010.
Shawnee County ranked third in population at 178,909 with a slight 0.5% growth in the past decade followed by Wyandotte County with a population of 169,245, an increase of 7.5%, and Douglas County’s 118,785 population, growing 7.2% since 2010.
Four of the state’s 10 largest cities remain in Johnson County with Overland Park as the second largest city with a 2020 Census population of 197,238 followed by Olathe, fourth largest at 141,290; Shawnee, seventh largest, 67,311; and Lenexa, eighth largest, 57,434. Wichita remains the largest city in Kansas with a population of 397,532.
Overland Park had the largest amount of growth compared to cities in Johnson County with 23,866 new residents in the last decade.
Spring Hill, with a 2020 population of 4,932 in the Johnson County portion of the city, had the largest percentage of gain by growing 59% since 2010 when the county portion was 3,100. Adding the portion of the city in Miami County, Spring Hill has a total population of 7,952.
Overall, Johnson County has six of the top 10 cities in sheer growth and eight of the top 10 cities in percentages of growth.
The Kansas population increased 3% to 2,937,880, according to the 2020 Census. It was the smallest growth of the state since the 1910 Census. Eighty counties, mostly rural, out of the state’s 105 counties lost population over the past decade.
The 2020 Census placed the nation’s population at 331,449,281, an increase of 7.4% from 2010. Nationally, the Hispanic or Latino population, which includes people of any race, grew 23%. In Kansas, the Hispanic or Latino population increased to 13% from 10.5% a decade ago.
In Johnson County, the Hispanic or Latino population has grown by 24.55% from 38,989 in 2010, representing 7.16% of the county population, to 54,389 in 2020, or 8.92%.