Population, Diversity and Immigration in Houston

One of the strongest forces to shape the region, Houston’s diverse population is also its greatest asset.

In the last decade, the population in Houston’s three-county region — due to strong levels of international and domestic migration — grew substantially and became far more diverse.

The data

More than 6.2 million people call the Houston-area home

Harris County covers 1,777 square miles in the region, followed by Montgomery County with 1,077 square miles coverage, and Fort Bend County with 885 square miles. Together, the three counties cover 40% of the nine-county Houston-Sugar Land-The Woodlands Metropolitan Statistical Area (MSA).¹

How many Houstonians are there, and where do they live? Houston’s three-county region has a total population of over 6.2 million that accounts for 87% of the Houston MSA population.

Each county has witnessed remarkable population surges over the past few decades. In Fort Bend County, the population doubled over the last two decades, reaching nearly 860,000 in 2021. Montgomery County’s population also doubled, soaring from 294,000 in 2000 to 650,000 in 2021. In Harris County, the most populous county in the region and the state, the population climbed above 4.7 million.

This recent population growth is a part of a robust historical trend. Since 1980, Greater Houston’s population growth has consistently outpaced national and statewide trends. Fort Bend and Montgomery counties, in particular, have emerged as leaders, regularly recording growth rates that are double or even triple those observed in Harris County and Texas. The implications of this sustained population growth are profound, shaping Houston into a national power player and propelling economic growth in the region.

Houston’s racial/ethnic composition grows more diverse

Since 2000, the racial composition of Greater Houston’s population has changed significantly. The number of Hispanic and Asian-American residents has boomed, propelling the region into one of the most ethnically diverse in the country.

In each of Houston’s three counties, the number of residents that identify as people of color (non-white) grew faster than the population of white residents. This has driven the profound demographic change that the Houston area has undergone over the last few decades.

In 2021, Asian American (21.5%), Black (20.8%), and Hispanic (25.5%) residents comprised two-thirds of Fort Bend County’s population. White people, comprising one-third of the county’s total population, grew steadily, but slower compared to other racial/ethnic groups. While Fort Bend County’s Hispanic and Black population remained relatively stable, the Asian-American population nearly doubled in size between 2000 and 2021.

Harris County has been majority-people-of-color since 2000, and recent data show that people of color continue to propel the county’s growth. Hispanics have been the largest ethnic group since 2010, and by 2021 they comprised 44% of the total population. Since 2000, the county has seen the most growth in the Asian American (95%) and Hispanic (87%) population, with more modest growth in its Black population (46%). Notably, Harris County is the only county in Greater Houston where the number of white residents declined between 2010 and 2021.

With 650,000 residents in 2021, Montgomery County’s population has doubled over the last two decades. While the county remains mostly white (60.9%) — with its Hispanic (26.4%), Black (6.2%) and Asian American (3.9%) populations making up one-third of the county’s total population in 2021 — Montgomery County has experienced incredible growth in Asian-American (679%), Hispanic (361%) and Black (299%) populations between 2000 and 2020.

In Houston’s three-county area at large, the vast majority (78%) of children under five are people of color, indicating that Houston will continue to become more racially diverse over time. Fort Bend County shows a somewhat-even distribution of races/ethnicities in this age group. A vast majority of Harris County’s youngest population are people of color (82%). In contrast, half of children under five in Montgomery County are white (62%).

Houston’s three-county region soars 134% over four decades

Population distribution by age group offers a more precise way to characterize the population change by revealing which age groups are driving the growth in the region, which informs how resources may need to be allocated to meet emerging needs.

While Houston’s population boomed during the 2010s, the growth was uneven among age groups. Older adults (65 and older) saw the greatest percentage increase in total population in Fort Bend, Harris, and Montgomery counties from 2010-2021. The rise in older adults was especially pronounced in Fort Bend, where the total number of residents aged 65+ soared 222%. In all three counties, the second highest growth rate was among children aged 5-17. Montgomery (39%) and Fort Bend (37%) counties led the region’s growth.

Population in Greater Houston could double to 12 million by 2050

Analyzing population growth by age group provides insights into the region’s demographic future. Population projections are used to make decisions about how to prepare for future demand and needs for resources like food, water, energy, housing, and services. By analyzing how Houston’s population grew the last few decades, we better understand what the impacts of that growth will be.

The following are demographic forecasts for Houston’s three major counties. By 2050,

• Fort Bend County is projected to reach over 2 million people with a demographic breakdown of 40% Asian, 24.9% Hispanic, 22.2% white, and 12.9% Black.
• Harris County is projected to reach almost 8 million people with demographic breakdown of 42.4% Hispanic, 20.8% white, 19.5% Asian/Other, and 17.6% Black.
• Montgomery County is projected to reach 1.5 million people with a demographic breakdown of 41% white, 40% Hispanic, 13.3% Asian/Other, and 7.7% Black.

Immigration in Houston drives population growth

What is driving Houston’s population growth? Generally, the primary drivers of population growth are the result of three factors: levels of fertility, mortality, and migration. Simply put, our population would grow as long as the number of births exceeds the number of deaths — this is known as the natural population increase. Migration, on the other hand, measures the movement of people from one area to another, and net migration measures the difference between the number of people who move into and out-of an area. Migration can be domestic, referring to the migration of people within the United States, or international, which refers to the movement of people across national borders.

From 2010 to 2020, population growth in Fort Bend and Montgomery counties was largely driven by domestic migration. In Fort Bend, natural changes in population accounted for an additional 61,200 people, while 143,900 people moved into the county from elsewhere in the United States. In Montgomery County, natural changes in population resulted in an additional 34,500 residents, while 121,900 people moved to the county from elsewhere in the United States. This trend continues: in 2020, the domestic migration rates for Fort Bend (81%) and Montgomery (85%) counties exceeded the statewide (58%) and national rates (24%). 

The story is different in Harris County. Overall, net migration was positive from 2010-2020; but that was driven almost entirely from international migration rather than domestic. In fact, net migration has been negative in Harris County since 2017. This decline is driven by reduced international migration and worsening rates of population loss from domestic migration. That being said, Harris County is still experiencing population growth from natural increases. From 2010 to 2020, natural changes in population resulted in an additional 442,600 Houstonians.

Immigrants comprise a larger share of the Houston area than the nation overall

The Houston area owes much of its economic success and cultural vibrancy to the immigrants who have made this region their home. While categorized under one label, the “immigrant population” comprises people who were born outside the United States (foreign born), including naturalized citizens, legal permanent residents, temporary residents, and unauthorized immigrants.

More than one in four individuals living in the Houston three-county region are immigrants. Among the three counties, Fort Bend County is home to the highest share of immigrants (32%) with Montgomery County home to the lowest (15%). For the past few decades, Houston’s immigrant community has grown at a faster rate than the U.S.-born population, and this trend is showing no sign of slowing in Fort Bend. This makes it likely that immigrants will continue to constitute a greater proportion of Houston’s population in the coming years.

After steady growth, the number of new Americans decline during the pandemic

What are naturalized citizens? When a foreign-born resident becomes naturalized, they become a legal citizen of the United States and now have the same constitutional rights and civic responsibilities as a native-born citizen, including eligibility to vote. To become a naturalized citizen, immigrants must meet certain requirements, including completing a five-year period of lawful permanent residence, demonstrating basic proficiency in English, U.S. history, and civics, and passing a background check. Naturalized citizens tend to have higher incomes and rates of homeownership compared to non-citizens.²

The number of residents achieving lawful permanent resident status in Texas and the Houston MSA has declined sharply after peaking in 2019. The same is true for the number of residents becoming naturalized citizens. Both declines can be attributed to the COVID-19 pandemic and the Title 42 expulsion policy that accompanied it. Title 42 gave the government greater authority to expel immigrants in the name of public health. This reduced the incentives for immigrants to migrate to the U.S., made it more difficult to achieve asylum, and drastically slowed legal immigration. Even following the expiration of Title 42, the number of immigrants seeking to enter the United States has remained depressed.

Most unauthorized immigrants in the Houston-area have lived in the country for five or more years

How many unauthorized immigrants are in the U.S.? About 11 million unauthorized immigrants reside in the nation, representing about 24% of the total immigrant population in the U.S. About 16% of the nation’s unauthorized immigrant population — around 1.7 million — live in Texas. 

How many unauthorized immigrants are in Houston? The Migration Policy Institute estimates that 481,000 unauthorized immigrants live in Harris County, 39,000 in Fort Bend County, and 28,000 in the area of Montgomery, Chambers, and Liberty counties. Harris County is home to the second largest unauthorized immigrant community in the nation — Los Angeles County leads the nation with 951,000 unauthorized immigrants.

Most unauthorized immigrants in the U.S. and Texas have lived in the country for five or more years. The share of undocumented immigrants by years of residence is about evenly distributed across Houston’s three-county area. Fort Bend County has the highest proportion of undocumented immigrants who entered the country in the last five years (30%), while Montgomery County has the highest proportion of unauthorized immigrants who have lived in the U.S. for 20 or more years (25%). Harris County, meanwhile, has the highest proportion of unauthorized immigrants who have lived in the county for 10-14 years (19%).

The distribution of the unauthorized community by age is fairly consistent across the U.S., Texas, and Houston’s three-county area. Most unauthorized residents — 55% — range from 25 to 44 years old. The smallest groups of unauthorized immigrants are under the age of 16 and over the age of 55.

Where are most unauthorized immigrants in Houston from? People from Mexico and Central America are the majority of unauthorized immigrants in Houston’s three-county region. In Fort Bend County, 35% of unauthorized immigrants come from Asia (compared to 15% nationally), and in Montgomery County 85% of unauthorized immigrants hail from Mexico or Central America.

More than 140 languages are spoken in the Houston area

One of the main ways in which diversity in Houston manifests itself is in the number of languages spoken in the region. Houstonians are multi-linguistic: English, Spanish, Vietnamese, Chinese, and Hindi are all spoken at high rates.

Other than English, the most commonly spoken language across Houston’s three-county region is Spanish. Following Spanish, the most commonly spoken languages are Vietnamese, Chinese, Arabic, and other Indo-European languages, such as French, German, Gujarati, Hindi, Italian, Russian, Urdu, etc. Fort Bend County has the greatest linguistic diversity inHouston’s three counties.

The Houston region grows more diverse

While the Houston area is remarkably diverse, diversity does not necessarily entail that residents of different backgrounds will come into contact with each other. Historically, the United States’ major cities — including Houston — were highly segregated. Residents of different racial and ethnic backgrounds can not interact and connect with each other if they are forcefully separated by exclusionary zoning codes, interstate highways, and social stigma. While explicit segregation is illegal, we continue to see its impact in the make-up of our modern neighborhoods. 

The fractionalization index uses population data to measure the likelihood that two random people in a given area will be of a different race or ethnicity. Scores range from 0 to 1, with 0 indicating that two randomly chosen people belong to the same ethnic group, and one indicating maximum diversity (a 100% chance that two randomly chosen people are of different racial/ethnic backgrounds).

In 2020, Fort Bend County had the highest level of diversity in Houston’s three major counties, scoring a 0.76 in the fractionalization index. Harris County scored a 0.7, while Montgomery County scored a 0.57, indicating it is less diverse. Neighborhoods in both Fort Bend and Harris counties are more diverse than the average American and Texan neighborhood (0.62 and 0.67, respectively).

Fort Bend, Harris, and Montgomery counties scored higher on the fractionalization index in 2020 than in 2010, indicating these places grew more diverse in the last decade. Fort Bend County’s score increased from 0.74 to 0.76; Harris County’s from 0.69 to 0.70; and Montgomery County saw the greatest increase, jumping from 0.45 to 0.57 in the fractionalization index.

Nearly 220,000 veterans live in Houston’s three-county region

A veteran is a person who served in the active military, naval, or air service, and who was discharged or released under conditions other than dishonorable. As of 2021, there are over 16 million veterans in the United States. Texas is home to the largest number of veterans with over 1.4 million in the state.

Nearly 220,000 veterans live in Houston’s three-county region, with the greatest concentration of vets in Montgomery County (7.2%). About 4% of the population in Fort Bend and Harris counties are vets.

Compared to non-veterans, veterans are about twice as likely to have a disability, and they are half as likely to live below the poverty threshold.

Helpful Articles by Understanding Houston:

• Houston is Diverse
• Houston is Vibrant
• Houston is Changing
• Key insights from our webinar on housing inequities
• Houston’s Three-county Region Accounts For a Quarter of Texas’ Population Growth