The magnitude 4.1 quake struck shortly before 6 p.m. just outside San Jose, which is home to a million people and surrounded by heavily populated suburbs.
Twitter lit up with reports from slightly shaken people in the area. Most said it was just a quick jolt, and many wondered whether they had really felt a quake.
Police and fire officials in and around San Jose reported no damages, injuries or other problems.
The earthquake came as deadly wildfires were raging near the San Francisco Bay Area, though the closest of the blazes is 100 miles from the quake’s epicenter.