Climate change threatens the health and well-being of California’s diverse population of nearly 38 million people and poses immense challenges for achieving health equity. While all Californians are impacted by climate change, the populations most vulnerable to the health impacts of climate change are the same communities that experience health inequities, or systemic differences in health status that are preventable and unfair. Low-income families, some communities of color, people with existing health conditions such as chronic diseases and mental health problems, children and seniors, people experiencing homelessness, outdoor workers and farmers, immigrants, especially those with undocumented status, tribal nations, and isolated people are most vulnerable to the impacts of climate change.