Earthquakes in California occur very frequently. On average, Southern California experiences an earthquake approximately every three minutes. While most of these quakes are minor and too small to be felt, about 15 to 20 earthquakes with a magnitude of 4.0 or greater happen annually. Additionally, California typically has two to three earthquakes per year that are strong enough (magnitude 5.5 or higher) to cause moderate damage to structures. Overall, California experiences dozens of earthquakes each day, but the vast majority are very small and go unnoticed without sensitive equipment detecting them.

This high frequency is due to California's position along significant fault lines, including the San Andreas Fault, and the state is the second most seismically active in the U.S., behind Alaska.

Therefore, while small tremors happen almost continuously, larger felt earthquakes occur on average multiple times per year.