Summary (tl;dr)

A magnitude 5.6 earthquake struck Northern California's Mendocino County this morning, triggering widespread ShakeAlerts and causing power outages and some reported injuries.

Essential Background

California is highly seismically active due to its location on the Pacific Ring of Fire and the presence of major fault lines, including the San Andreas Fault system. Earthquakes are a regular occurrence, leading to the development of early warning systems like ShakeAlert to provide residents with crucial seconds of warning before shaking begins.

The Full Story

A preliminary magnitude 5.6 earthquake hit Mendocino County, Northern California, at 8:10 a.m. on Wednesday, June 24, 2026, with its epicenter located approximately 7 miles north of Redwood Valley. The seismic event prompted ShakeAlert notifications across a wide area, including the Sacramento region and the Bay Area, allowing some residents to receive warnings before feeling the tremor. The earthquake, which occurred at a depth of about 5 miles, was strong enough to knock items off shelves and cause power outages for thousands of Pacific Gas & Electric Co. (PG&E) customers in communities like Willits, Covelo, and Laytonville. While some injuries have been reported, officials confirmed no fatalities. Several aftershocks, including a magnitude 2.5 tremor, followed the main quake. The Mendocino County Superior Courthouse in Ukiah was temporarily evacuated as a precaution. Seismologists suggest the earthquake likely originated along the Maacama fault, which is connected to other major faults in the Bay Area.

Why It Matters

This earthquake highlights the ongoing seismic risk in California and the importance of earthquake preparedness. The widespread distribution of ShakeAlerts demonstrates the effectiveness of early warning systems in providing valuable time for people to take cover and for emergency services to prepare. Although the damage appears relatively localized to Mendocino County with no major structural damage reported, the power outages and reported injuries underscore the immediate impact even moderate earthquakes can have on communities. The incident also serves as a reminder for residents to be aware of earthquake safety protocols and the potential for aftershocks.

Geographic Location

• Redwood Valley, Mendocino County, California, United States (epicenter of 5.6 magnitude earthquake)
• Willits, Mendocino County, California, United States (power outages, strong shaking)
• Ukiah, Mendocino County, California, United States (courthouse evacuation)
• Mendocino County, California, United States (overall affected region, reported injuries, power outages)
• Sacramento, Sacramento County, California, United States (shaking felt, ShakeAlert notifications)
• San Francisco Bay Area, California, United States (ShakeAlert notifications, shaking felt)