Valley Fever Is Spiking in California—Here’s What You Need to Know

After a cold start to summer, rising temperatures across California are now triggering a dangerous increase in Valley Fever cases—especially in the Central Valley.

Valley Fever (also called coccidioidomycosis) is a fungal infection caused by Coccidioides spores that live in dry soil. As the ground dries out following a wet winter, these spores become airborne—especially during hot, dusty, and windy days.

Why Is Valley Fever Spiking Now?

According to recent news reports, counties like Sacramento and Stanislaus have already surpassed last year’s Valley Fever case numbers—and summer isn’t over yet. Experts believe climate change is playing a role, as longer dry periods make spore release more likely.

• Stanislaus County: 83 cases so far in 2025 vs. 81 total last year
• Sacramento County: 52 cases in 2025 vs. 44 in all of 2024

How Does Valley Fever Spread?

• Spores start in the soil, bloom after rain, and become airborne as things dry out.
• Inhaling these spores—especially in areas with dry, dusty conditions—can lead to infection.
• There is currently no vaccine, though one is in development.

What Are the Symptoms?

Symptoms often mimic the flu or a lingering cold:

• Fever
• Cough
• Fatigue
• Shortness of breath
• Weight loss
• Muscle aches or joint pain

In most people, symptoms are mild. However, Valley Fever can cause serious illness, such as pneumonia or even meningitis in rare cases.

‍Who’s Most at Risk?

Those who work outdoors or disturb soil are most vulnerable:

• Construction crews
• Farm workers
• Landscapers
• Anyone exposed to windy, dusty conditions

How to Protect Yourself

While you can’t eliminate all risk, mitigation steps include:

• Wearing an N95 or KN95 mask when outdoors in dusty conditions
• Avoiding outdoor activity during high winds
• Keeping windows closed on dry, windy days
• Seeing a doctor early if symptoms develop—especially after outdoor exposure

Get Checked If You’re Feeling Sick

If you’ve recently been outdoors and are experiencing fatigue, cough, or flu-like symptoms that won’t go away, ask your doctor about Valley Fever. Early treatment can help prevent complications.