Finding · updated October 5, 2026
Southern California has an earthquake every half hour — you feel almost none of them
In 121 days the USGS logged 5,578 earthquakes under Southern California — one every 31 minutes. 98% were too small to feel; the biggest was an M4.4.
Southern California is never still. Over 121 days (June 6–October 4, 2026), the USGS seismic network we track logged 5,578 earthquakes beneath the region — about 46 a day, or one roughly every 31 minutes, around the clock. Almost none of them reached human awareness.
The median quake measured just M1.0. 95% of them came in under magnitude 2.0, and 98% under magnitude 2.5 — the rough line below which an earthquake is essentially never felt, even by someone standing above it. Only 84 of the 5,578 reached M2.5 in the whole two weeks: about one every other day, and still small. The largest was an M4.4.
| magnitude | quakes | share |
|---|---|---|
| below 1.0 — micro | 2,808 | 50.3% |
| 1.0 – 1.9 | 2,479 | 44.4% |
| 2.0 – 2.9 | 263 | 4.7% |
| 3.0 and up | 28 | 0.5% |
Where the biggest ones were:
- M4.4 — 2 km ESE of Frazier Park, CA (Jul 12)
- M4.3 — 18 km WSW of Johannesburg, CA (Jul 13)
- M3.8 — 4 km SE of Piru, CA (Sep 29)
This is the texture of living on an active plate boundary: the ground moves constantly, almost always far below the threshold of feeling, and the rare jolt that does register is drawn from the same steady background hum. It is also the case for paying attention to the small ones — the rate and location of micro-quakes is exactly the raw material seismologists watch.