Valley fever cases in California continue to rise, with the California Department of Public Health (CDPH) reporting over 5,500 provisional cases in the first half of 2025. This follows a record year in 2024, when nearly 12,500 cases were reported, a significant increase from the annual average of 7,000-9,000 cases between 2017 and 2023. The illness remains most prevalent in the southern San Joaquin Valley but is also increasing in the northern Central Valley and Central Coast.
Valley fever, or coccidioidomycosis, is caused by a fungus found in soil and dirt in certain regions of California. People can become infected by breathing in dust containing the fungus, especially during late summer and fall. The disease often presents symptoms similar to COVID-19 or flu—such as cough, fever, trouble breathing, chest pain, and tiredness—and can sometimes lead to serious lung infections like pneumonia.
“California had a record year for Valley fever in 2024 and, so far, case counts are high in 2025. Valley fever is a serious illness that’s here to stay in California. We want to remind Californians, travelers to California, and their healthcare providers to watch for signs and symptoms of Valley fever to help detect it early,” said CDPH Director and State Public Health Officer Dr. Erica Pan. “If you have been sick with symptoms like cough, fever, trouble breathing, and tiredness for more than 7 to 10 days, please talk to a healthcare provider about Valley fever, especially if you’ve been outdoors in dusty air in the Central Valley or Central Coast regions.”
Research indicates that changes in climate may be contributing to the spread of Valley fever. Wet winters following droughts create favorable conditions for fungal growth; subsequent dry and windy weather helps release spores into the air. Increased construction and other activities that disturb soil are also believed to play a role.
The CDPH advises residents and visitors—especially those living or working outdoors—to take precautions such as staying indoors on windy days when dust levels are high; keeping windows closed while driving through dusty areas; wetting soil before digging; and considering N95 respirators when exposure cannot be avoided.
While most people recover without treatment, some develop severe or chronic forms of the disease that require medical care or hospitalization. Certain groups—including older adults (over age 60), people with diabetes or weakened immune systems, pregnant individuals, Black people or Filipinos—are at higher risk for severe illness.
Valley fever cannot be transmitted from person-to-person or animal-to-animal. Diagnosis requires laboratory testing by a healthcare provider. For further information about prevention measures or resources for healthcare professionals—including updated diagnostic guidelines—the public can visit the CDPH’s Valley Fever website.
