When Was California’s Last Major Earthquake?
If you live in California, the question isn’t if another earthquake will strike—it’s always when. That’s why the question “When was California’s last major earthquake?” isn’t just about history. It’s about awareness, preparedness, and learning how to read seismic risk in real time.
The Last Major Earthquake in California
California’s most recent major earthquake struck on December 5, 2024, registering a magnitude 7.0. The event shook Northern California and surrounding regions, serving as another reminder of the state’s seismic reality.
But here’s the part most people miss: this wasn’t just another unpredictable natural disaster. At Earling, our models had already flagged a high-risk seismic time window in California as early as November 25, 2024. In other words, we were tracking elevated earthquake probabilities nearly two weeks before the ground actually moved.
Forecasting vs. Aftershocks
Most public attention focuses on earthquakes after they happen. But communities, businesses, and governments benefit far more from knowing beforehand when the risk is shifting.
That’s exactly where Earling comes in. Since September 2020, when we began covering California and Nevada, we’ve consistently detected high-risk windows ahead of major events. These forecasts aren’t vague long-term outlooks—they are short-term risk signals, usually lasting 5 to 14 days, that highlight when seismic activity is most likely.
To put it in perspective:
- Dec 20, 2021 (M6.2) – Forecast window opened Dec 15.
- Dec 20, 2022 (M6.4) – Forecast window opened Dec 15.
- Dec 5, 2024 (M7.0) – Forecast window opened Nov 25.
Each of these events was preceded by a forecasted high-risk period detected by our system.
Why This Matters for California
California is home to critical infrastructure—energy grids, hospitals, schools, supply chains. For leaders managing risk, the difference between reacting after the fact and preparing before can mean billions saved and lives protected.
As consultants often remind decision-makers: risk management is less about predicting the exact second of an event and more about recognizing when probability curves change sharply. That’s precisely what our seismic forecasting technology delivers.
Moving Forward
So, when was California’s last major earthquake? December 5, 2024.
But the more valuable question might be: when will the next high-risk window open?
Earling’s mission is simple: shift the conversation from reaction to preparation. To learn how our earthquake forecasting insights can be built into your resilience strategy, schedule a consultation with our team today.