Two of California’s fast growing cities in 2025 were in South San Joaquin County.

Mountain House was the 4th fastest growing at 5.64 percent and Lathrop was the 5th fastest growing at 5.5 percent.

Manteca was the 15th fastest growing at 1.5 percent.

Ripon, meanwhile lost 123 residents.

And when it came to just those cities with a population of 30,000 or more, Mountain House was the state’s fastest growing city and Lathrop the second fastest growing city. California has 483 cities.

The snapshot of statewide population estimates for cities and counties as of Jan. 1, 2026 was released this month by the California Department of Finance.

“Lathrop’s growth is a reflection of the strength of our community, and the confidence families continue to place in our city,” said Lathrop Mayor Paul Akinjo.

“People are choosing Lathrop because they see opportunity here. As we grow, our responsibility is to keep planning thoughtfully, investing in infrastructure, and protecting the quality of life that makes Lathrop such a special place to call home.”

Lathrop broke the 40,000 population barrier coming in at 40,942 residents.

That means the city has increased in population by more than 500 percent since it was incorporated with 6,841 residents in 1989.

By comparison, Manteca has seen just over an increase in population of 130 percent between 1990 when it had 40,773 residents to 96,511 at the end of 2025.

“Growth brings opportunity, but it also brings responsibility,” said City Manager Stephen J. Salvatore.

“The City of Lathrop remains focused on managing growth in a way that supports families, strengthens neighborhoods, and ensures our infrastructure and services keep pace with the needs of our residents.”

Manteca added 809 single family homes in 2025 for 100 percent of its new housing production.

In comparison, Lathrop added 765 single family homes for 94.8 percent of all of its housing units with the remaining 42 units being multiple-family units such as apartments or halfplexes.

Manteca was ranked first statewide for the total number of single family homes built at 809 while Lathrop was third at 765.

Lathrop also ranked fifth among California cities under 300,000 residents for the largest numeric population increase.

Lathrop added 2,151 residents, Mountain House 1,639 residents, Manteca 1,560 residents, and Tracy 929 residents.

With 99,705 residents, Tracy is posed to surpass the 100,000 population mark by year’s end.

Manteca is likely to top 100,000 residents by the end of 2027.

Tracy is the fourth largest city in the three county Northern San Joaquin Valley region consisting of San Joaquin, Stanislaus, and Merced counties.

It has just 230 less residents than Merced that added 780 people last year to reach 780.

The two largest cities in the region both had population declines.

Stockton lost 64 residents and now has a population of 322,436 while Modesto lost 475 residents and is now at 220,048.

Statewide trends

A full year of restrictive federal policy changes cut legal international migration to California by more than half in 2025 and drove a slight decline (less than 1/7th of 1%) in California’s overall population.

Absent these changes, California’s population as of Jan. 12 would have seen a slight increase of 66,000 over the same period. Because of these federal changes, the state experienced a small decline of 54,000.

The 0.14-percent decline to 39,593,000 marks the first year of population loss after three consecutive years of population increases following the COVID-19 pandemic.

From 2021 to 2024, California’s growth in net international migration was driven by both legal immigrants and the expansion of international humanitarian migration programs.

Net legal international migration has been a significant driver of California’s overall population, offsetting declines in natural increase — the net number of births and deaths — and net domestic migration from California.

While natural increase added in 2025, by 108,200 persons, it is down 4,500 from 2024.

Net domestic out-migration from California increased to 288,600 in 2025.

To contact Dennis Wyatt, email dwyatt@mantecabulletin.com