The last widely cited big earthquake in California was the Northridge earthquake on January 17, 1994 , with a magnitude of 6.7.

Context

California has had many earthquakes since then, but “big” can mean different things:

  • Largest recent major quake : Northridge in 1994, a damaging 6.7 event.
  • Historic larger quakes : California’s state earthquake history also tracks much larger, older events such as the 1857 Fort Tejon earthquake and earlier estimated quakes.

Why this answer can vary

If you mean the last damaging quake of note , Northridge is the usual reference point in public summaries. If you mean the largest California earthquake in recent years , you’d need a current recent-quakes list, since California has ongoing seismic activity.

Bottom line: for a quick answer, Northridge in 1994 is the standard “last big earthquake in California” people usually mean.