Climate Change

Indicators of Climate Change in California

The 2026 edition is organized into seven volumes, including 49 indicators and eight tribal reports. The report documents accelerating and compounding climate impacts across California's water systems, wildfires and public health, terrestrial ecosystems, and coastal and marine environments, with attention to disproportionate impacts on tribes, outdoor workers, and low-income households.

Indicators of Climate Change: Impacts on California Tribes

OEHHA recognizes the value of tribal knowledge in reporting on, and raising awareness of, climate impacts.

Human Health Impacts of Climate Change

OEHHA focuses on human health studies relating increased temperatures to adverse health outcomes such as death and illness including hospital visits, emergency room visits, and birth defects. OEHHA has contributed to the growing body of literature linking deleterious health effects to increasing temperatures and heat waves. These studies have helped identify groups who are vulnerable to heat-related mortality and illness.

Recent Research on Climate Change in California: A bibliography

OEHHA has compiled information relevant to climate change and its impacts in an annotated bibliography with an emphasis on California. This annotated bibliography is intended as a source of current and emerging scientific information on climate change for environmental and public health agencies, the research community, non-government organizations, and the public.

Indicators of Climate Change: Past Reports

Collection of past Indicators of Climate Change in California reports.

Reports, Notices, Documents

Explore the indicators that show how climate change is affecting California. These scientifically-based measurements track trends in various aspects of climate change and are useful for communicating information about the climate change issues confronting the state.

OEHHA compiles environmental indicators tracking the impacts of climate change in California, which are already occurring. 

The report presents 36 indicators that show how climate change is affecting California. The report is intended to promote scientific analysis to inform decision-making on mitigating and adapting to climate change and to serve as a resource for decision makers, scientists, educators, and the public.

Report covers temperature, wildfires, drought, Sierra Nevada snowmelt, species migration, shifting ranges of many species of California plants and animals.

OEHHA convened a workshop to improve upon and explore new metrics for tracking climate change and its impacts on California’s water resources, oceans, fish and wildlife, forests, agriculture, and the health and well-being of the state’s residents.