Valley Fever Cases in California Escalate

Valley fever is on the rise in California with over 5,500 provisional cases reported through the first six months of 2025. Last year, California reported nearly 12,500 cases—the highest year on state record. Valley fever is caused by a fungus that grows in some areas of California and can cause symptoms that look like COVID-19 or flu. Valley fever can also cause serious lung infections like pneumonia.

Rates of Valley fever continue to be highest in the southern San Joaquin Valley region of California, but cases have been increasing in other areas such as the northern Central Valley and the Central Coast.

Research suggests the rise and spread of Valley fever may be linked to changes in climate. Wet winters after drought help the fungus grow, and dry, windy weather in the following summer and fall can help the fungus get into the air. Increases in dirt-disturbing activities, like construction in high-risk areas, may also contribute to an increase in cases.

People who live, work, go to school, or travel in areas where Valley fever is common are at risk of becoming sick. Although most people with Valley fever get better on their own and don’t need treatment, for some people it can become severe, chronic, or even fatal without care.

People and pets can get Valley fever by breathing in dust from outdoor air that contains the fungus. The disease is not contagious and cannot spread from one person or animal to another. Some practical tips to reduce your chances of getting Valley fever include:

• When it is windy outside and the air is dusty, stay indoors and keep windows and doors closed.
• Before digging, wet down soil and dirt to prevent stirring up dust into the air.
• Consider wearing a properly fitted N95 respirator (mask) if you must be in dusty air in these areas.