Key takeaways

• Climate change endangers health. Extreme heat waves and wildfires have harmed the mental and physical health of millions of Californians.
• Immigrants' health under threat. A rising number of adults who witnessed hate incidents said the victim was targeted based on perceived immigration status, ancestry, origin or language.
• Updated race and ethnicity measures. Standards reflect the 2024 revisions to federal guidelines, including disaggregated data on Middle Eastern and North African communities.

The new annual California Health Interview Survey (CHIS) data released today provide a more precise look at how the 2025 wildfires affected Californians' health and well-being, while also revealing troubling trends in the health of immigrants, low-income individuals, and transgender and gender expansive communities.

The 2025 CHIS data show:

• 500,000 more California adults said their mental health was harmed as a result of wildfire smoke in the past two years, rising from 1.6 million in 2024 to 2.1 million in 2025.
• 45% of the lowest-income Californians struggle to pay for enough food.
• More people who witnessed hate incidents cited ancestry, origin, language or perceived immigration status as the reason the individual was targeted.

"We can't fix what we don't know. Providing data on a wide range of health and health-related topics and digging deep into the social drivers of health is what CHIS has specialized in for 25 years," said Ninez A. Ponce, principal investigator of the California Health Interview Survey and director of the UCLA Center for Health Policy Research (CHPR), which runs the survey. "And we do more than produce data. We make sure data are easily available to everyone to help inform policies and programs that can improve the health of all Californians."

Since its launch in 2001, CHIS has collected data on health insurance coverage, access to care, chronic conditions, the social drivers of health and health needs, and has expanded to hundreds of other topics that collectively reveal patterns showing how people's day-to-day experiences are associated with health outcomes. CHIS findings have informed legislation, budgets, policy, advocacy and research.

CHIS reveals how wildfires affect the health of Californians

In January 2025, fires devastated the Altadena and Pacific Palisades neighborhoods in Los Angeles County, and the updated CHIS data help capture the extent of the impacts. Nearly 30% of L.A. County adults - an estimated 2.3 million people - said they or members of their household personally experienced wildfires in the previous two years. By comparison, in 2024, 6.6% of L.A. County adults said that they or members of their household personally experienced wildfires in the previous two years (503,000).

Statewide, 21.8% of adults reported in 2025 that they or a household member personally experienced wildfires in the past two years (6.5 million), compared with 10% of adults who reported that in 2024 (2.9 million).

And 53.4% of California adults reported in 2025 that they or a household member personally experienced smoke from wildfires in the past two years (16 million), up from 37% of adults in 2024 (10.9 million).

The data also spotlight how wildfires affect health. Adults who experienced wildfires in the past two years and said their mental health was harmed increased from 17.2% in 2024 to 21.8% in 2025. With more adults experiencing wildfires, the number of adults whose mental health was harmed nearly tripled, from 506,000 to 1.4 million.

In Los Angeles County, the data show that 30.3% of adults who experienced wildfires reported mental health harm, compared with 21.8% of adults statewide.

The number of California adults who experienced smoke from wildfires in the past two years and said their mental health was harmed as a result also rose substantially - from 1.6 million in 2024 to 2.1 million in 2025.

Among adults in California who experienced wildfires in the past two years, 363,000 said their physical health was harmed, and 2.3 million who experienced wildfire smoke in the past two years said their physical health was harmed.

Among adults who experienced smoke from wildfires, nearly 1 in 5 (18.8%) in Los Angeles County said their physical health was harmed (the highest of any county) compared to 1 in 7 (14.4%) statewide.

Air conditioning and heat waves

According to the survey, more than half of California adults (52.5%) reported experiencing an extreme heat wave in the past two years. To further measure the impact of climate change on people's health, a new question was added in 2025 about Californians' access to and use of air conditioning.

More than 1 in 6 adults who experienced an extreme heat wave in the past two years do not have air conditioning at home (2.8 million people), and about 1 in 4 California adults who experienced an extreme heat wave said they used their air conditioning less because it was too expensive (3.3 million).

CHIS data also showed that 11.8% of adults without air conditioning at home and 11.6% of adults who used their AC less for any reason reported that their physical health was harmed by an extreme heat wave in the past two years. Among adults who have - and used - air conditioning at home, 7% reported harms to their physical health.

CHIS data also showed that 15.7% of adults without air conditioning at home and 17.8% of adults who used their AC less for any reason reported their mental health was harmed by an extreme heat wave in the past two years. Among adults who have - and used - air conditioning at home, 9.2% reported harms to their mental health.

"Data like this show that as our climate changes and heat waves increase, access to affordable air conditioning is not simply a luxury but a matter of health equity," said Todd Hughes, director of the California Health Interview Survey.

New race and ethnicity data available in the 2025 CHIS

This year's CHIS is among the first surveys in the nation to update race and ethnicity measures to reflect the 2024 revisions to federal SPD-15 guidelines, including disaggregated data on Middle Eastern and North African (MENA) communities.

More than 1 in 11 MENA adults (9.2%) in California experienced a hate incident in the past 12 months, similar to the rate for all California adults (8.7%).

These revisions to data collection also include a simplified approach to collecting Hispanic and Latino identification within a combined race and ethnicity question, as well as additional collection of detailed ethnic subgroups within each primary race and ethnicity category. To enable trending of data from previous years under the old guidelines, CHPR's free online query tool, AskCHIS, includes multiple versions of these race and ethnicity classifications using previous and current guidelines.

Other key findings from the 2025 California Health Interview Survey

Low-income Californians struggle with food insecurity

CHIS data on food insecurity are particularly relevant following the passage of the "One Big Beautiful Bill," which shifts more of the administrative costs of the Supplemental Nutrition Assistance Program (known as CalFresh in California) from the federal government to the states.

According to the 2025 CHIS, 45% of adults earning less than 200% of the federal poverty level ($64,300 for a family of four in 2025) reported not being able to afford enough food, and 32.6% receive CalFresh in California.

Vaping among young adults

Nearly 1 in 10 California adults ages 18-29 reported vaping in the past month (9.6%), more than twice the rate seen for adults ages 30 and older (3.7%), according to a fact sheet released today focused on young adult vaping.

Among young adults who vaped in the past month:

• Nearly two-thirds (64%) experienced at least one barrier to quitting, including: 31% who were afraid of failing to quit; 24% who were afraid of gaining weight; and 18% who were unable to access cessation medications due to cost.
• Only 1 in 5 who visited a doctor in the past year reported being advised to quit (20%).

Transgender and gender expansive adults and access to care

• Transgender and gender expansive adults were nearly three times as likely to report trouble finding a general doctor compared with all California adults (20.5% versus 7.6%).
• Transgender and gender expansive adults were twice as likely to report trouble finding a medical specialist (34.9% vs 16.9% for all California adults).

"As data have been disappearing at the federal level, it is critical that studies like the California Health Interview Survey continue to collect data on LGBTQ+ people, as well as immigrants, racial and ethnic groups, veterans, and people who are disabled to ensure that they're counted and their health needs are measured," Hughes said.

Immigrants' health

Looking at access to healthcare, 67.5% of non-U.S. citizen adults had a routine checkup in the past 12 months compared with 72.7% of U.S.-born citizens and 80% of naturalized citizens.

Among adults who witnessed a hate incident, 33.9% said the person was targeted for their perceived immigration status. The number of adults attributing a hate incident to someone's immigration status nearly doubled from 731,000 in 2024 to almost 1.5 million in 2025.

The 2025 California Health Interview Survey includes responses from 22,036 adults, 957 adolescents (ages 12-17) and 2,673 children, whose responses were provided by their parents.

"We're thankful to everyone who generously gives their time each year to participate in the survey," said Ponce, who is also a professor and Fred W. & Pamela K. Wasserman Endowed Chair in the Department of Health Policy and Management at the UCLA Fielding School of Public Health. "Without their cooperation and honesty, CHIS wouldn't exist, and all of us in California would lose an invaluable resource. CHIS is a powerful partnership among so many people, agencies, government and our supporters that helps us fulfill UCLA's responsibility to serve California."