Houston Population 2025 Growth Rate. Harris county, texas's estimated 2025 population is 4,888,913 with a growth rate of 1.11% in the past year according to the most recent united states census data. Census bureau in may 2025, with a growth projection of 1.5% annually for the next five.

Houston’s population is estimated to grow to 31.38 million, and austin’s is projected to jump to 22.29 million. Looking back last twelve years of houston’s population, the growth rate is strong and consistent ranging from 0.3% to 1.83%, adding around 7,000 to 41,000 people each.