Thornton is a city located in Adams County Colorado. Thornton has a 2023 population of 143,502. Thornton is currently growing at a rate of 0.31% annually and its population has increased by 0.94% since the most recent census, which recorded a population of 142,166 in 2020.
The average household income in Thornton is $101,588 with a poverty rate of 8.23%. The median rental costs in recent years comes to - per month, and the median house value is -. The median age in Thornton is 33.7 years, 32.9 years for males, and 34.4 years for females.
The city of Thornton is a home rule municipality located in Colorado. Situated in Weld and Adams counties, and the northeast region of the Denver-Aurora-Broomfield, CO Metropolitan Statistical Area, Thornton is about 10 miles north-northeast of downtown Denver, the most populous city of Colorado.
In 1960, four years after Thornton was incorporated as a city, the population stood at 11,353. The years between 1970 and 1980 saw a huge growth from 13,326 to 42,054, and an annual growth rate of 12.18%. This could be attributed to the annexation of neighboring communities.
As of 2019, the population of Thornton, Colorado stands at 137,000, with a percentage growth of over 1,000% in the 60 years since the city was incorporated in 1956. Colorado is now the 7th fastest-growing state in the U.S. with much of the growth in the Metro Denver area. Since the 1930s, Metro Denver's growth rate has outpaced the national average (http://www.metrodenver.org/do-business/demographics/population/) and this growth has included the area of Thornton.
Up until 1953, Thornton consisted exclusively of farmland. A purchase that year by Sam Hoffman saw the planning of the first community in Adams County. It was the first to offer full municipal services from a single tax levy, including services such as free trash pickup and recreation. By the end of 1955, Thornton had over 5000 residents in over 1,200 homes. Thornton was incorporated as a city a year later in 1956.
June of 1981 saw Thornton receiving one of the two most destructive tornados in the Denver metropolitan area’s history, causing damage totaling over $15 million. The second touched down in the nearby Denver suburb of Lakewood. These were followed by three more just 7 years later in 1988.
According to the most recent ACS, the racial composition of Thornton was:
Two or more races
Black or African American
Native Hawaiian or Pacific Islander
Average Family Size
Average Household Size
Rate of Home Ownership
Less Than 9th Grade
9th to 12th Grade
High School Graduate
High School Graduation Rate
The highest rate of high school graduation is among islander people with a rate of 100%.
The highest rate of bachelors degrees is among islander people with a rate of 50%.
Other Indo-European Languages
Asian and Pacific Island Languages
74.46% of Thornton residents speak only English, while 25.54% speak other languages. The non-English language spoken by the largest group is Spanish, which is spoken by 19.42% of the population.
Overall Poverty Rate
Male Poverty Rate
Female Poverty Rate
The race most likely to be in poverty in Thornton is Islander, with 50% below the poverty level.
The race least likely to be in poverty in Thornton is White, with 7.45% below the poverty level.
The poverty rate among those that worked full-time for the past 12 months was 1.56%. Among those working part-time, it was 13.31%, and for those that did not work, the poverty rate was 15.08%.
Overall Marriage Rate
Male Marriage Rate
Female Marriage Rate
The age group where males are most likely to be married is 55-64, while the female age group most likely to be married is 35-44.
Second Gulf War
First Gulf War
World War II
Less Than 9th Grade
High School Graduate
Bachelors or Greater
Veteran Poverty Rate
Veteran Disability Rate
Labor Force Participation
Non citizens include legal permanent residents (green card holders), international students, temporary workers, humanitarian migrants, and illegal immigrants.
Born in Thornton
86.87% of Thornton residents were born in the United States, with 52.84% having been born in Colorado. 8.66% of residents are not US citizens. Of those not born in the United States, the largest percentage are from Latin America.