Earthquake today in San Francisco Bay Area
Quakes recorded in the San Francisco Bay Area area over the past weeks, newest first.
Automatic information from scientific catalogues. In an emergency, follow your local emergency service and geological survey.
Magnitude
3.3
Minor (2 to 3.9)
27 km WSW of Westley, CA · 9/27/26, 2:21 PM UTC
Value
11
Magnitude ≥ 2,5 · 30 day
| Magnitude | Place | When | Depth | Category |
|---|---|---|---|---|
| 2.5 | 10 km ESE of Gilroy, CA | 10/15/26, 5:57 PM UTC | 5 km | Minor (2 to 3.9) |
| 3.1 | 7 km NW of The Geysers, CA | 10/15/26, 6:06 AM UTC | 3 km | Minor (2 to 3.9) |
| 2.9 | 8 km ESE of Cloverdale, CA | 9/30/26, 9:07 PM UTC | 5 km | Minor (2 to 3.9) |
| 2.5 | 1 km SSW of Anderson Springs, CA | 9/30/26, 8:48 PM UTC | 2 km | Minor (2 to 3.9) |
| 2.5 | 5 km W of Yountville, CA | 9/29/26, 4:06 PM UTC | 8 km | Minor (2 to 3.9) |
| 2.6 | 26 km WSW of Westley, CA | 9/27/26, 2:40 PM UTC | 4 km | Minor (2 to 3.9) |
| 3.3 | 27 km WSW of Westley, CA | 9/27/26, 2:21 PM UTC | 3 km | Minor (2 to 3.9) |
| 2.6 | 2 km NW of Hollister, CA | 9/23/26, 4:00 PM UTC | 7 km | Minor (2 to 3.9) |
| 2.5 | 10 km ENE of Milpitas, CA | 9/19/26, 10:52 AM UTC | 3 km | Minor (2 to 3.9) |
| 2.5 | 2 km ENE of Aromas, CA | 9/17/26, 6:14 PM UTC | -0 km | Minor (2 to 3.9) |
| 2.6 | 21 km E of Alum Rock, CA | 9/17/26, 3:07 AM UTC | 7 km | Minor (2 to 3.9) |
How to read these numbers
Position: 36.6° / 38.9° lat, -123.3° / -121.2° lon
Range
| Range | What it means |
|---|---|
| Micro (below 2) | Only seismographs record it. Nobody feels it. |
| Minor (2 to 3.9) | Sometimes felt near the epicentre, no damage. |
| Light (4 to 4.9) | Widely felt, objects rattle, damage is rare. |
| Moderate (5 to 5.9) | Damage to weak buildings near the epicentre. |
| Strong (6 to 6.9) | Can destroy buildings up to a hundred kilometres away. |
| Major (7 to 7.9) | Serious damage over a wide area. |
| Great (8 and above) | Destruction across hundreds of kilometres; tsunami risk. |
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How to read this page
How to read magnitude
Each whole point of magnitude multiplies the energy released by about 31.6. Between the largest on this list (3.3) and one of magnitude 2.5 the gap is orders of magnitude, not percent.
Where the list comes from
The 11 records come from the USGS catalogue (and, in Europe, from EMSC), filtered by the coordinate box for San Francisco Bay Area: 36.6° / 38.9° lat, -123.3° / -121.2° lon. Each row’s time is the catalogue’s own, in UTC.
Preliminary data
Magnitude and depth in the first hours are preliminary and shift as more stations enter the solution. This page issues no warnings and does not replace civil protection authorities.
What to do during shaking
The official advice is to drop, cover your head and hold on to something firm, away from windows, until the shaking stops. The full guide is on the United States preparedness portal.
Understanding seismic activity in San Francisco Bay Area
How often did the ground shake in San Francisco Bay Area in the last 30 days?
Over the last 30 days the catalogue recorded 11 earthquakes of magnitude 2.5 or above in the San Francisco Bay Area area, an average of 2.6 a week across the window this page covers.
Of the San Francisco Bay Area list, 11 came in below magnitude 4 (felt nearby, no damage), 0 between 4 and 5 and 0 at 5 or above — the normal proportion for any seismic region: many small, few large.
What does magnitude 3.3 mean in San Francisco Bay Area?
The largest event in the window for San Francisco Bay Area was magnitude 3.3 (Minor (2 to 3.9)), at 27 km WSW of Westley, CA, on 9/27/26, 2:21 PM UTC. The scale is logarithmic: that event released roughly 17 times more energy than one of magnitude 2.5. Below magnitude 4 the shaking is felt near the epicentre, usually lasts seconds and causes no structural damage.
Why does San Francisco Bay Area have earthquakes?
The area this page covers (36.6° / 38.9° lat, -123.3° / -121.2° lon) sits on the Pacific Ring of Fire, the belt of subduction zones that concentrates most of the planet’s earthquakes: there an oceanic plate dives beneath another, builds up stress and releases it in rupture. The median depth across this list is 4 km, and 100% of them are shallow (under 70 km), the band that shakes the surface hardest.
Words on this page
Magnitude
A measure of the size of an earthquake at its source, on a logarithmic scale: each whole point multiplies the energy released by about 31.6. A magnitude 7 event releases a thousand times more energy than a magnitude 5, not 1.4 times.
Standard definition by U.S. Geological Survey (USGS) — ANSS ComCat · Magnitude
Richter and moment magnitude
The Richter scale, from 1935, was calibrated for Californian seismographs and saturates: above 7 it stops separating events. Agencies now publish moment magnitude (Mw), computed from the seismic moment — fault area, slip and rock rigidity. That is what the news still calls "the Richter scale".
Standard definition by U.S. Geological Survey (USGS) — ANSS ComCat · Richter and moment magnitude
Focal depth
How many kilometres below the surface the rupture began. The USGS calls it shallow up to 70 km, intermediate from 70 to 300 km and deep beyond that. A shallow quake shakes the surface far harder than a deep one of the same magnitude.
Standard definition by U.S. Geological Survey (USGS) — ANSS ComCat · Focal depth
Epicentre
The point on the surface directly above the earthquake’s focus, where the rupture began. The place a catalogue names is the nearest geographical reference to the epicentre, not necessarily the worst-hit town: that depends on depth and on ground type.
Preliminary data
A measurement published as soon as it is collected, before the agency’s final review. It can be corrected or withdrawn: earthquake magnitudes shift in the first hours, air-quality readings are revised weeks later. Use it to plan your day, not for regulatory or legal purposes.
Aftershock
A smaller earthquake following a larger one on the same fault, while the rock settles into its new distribution of stress. Aftershocks are most frequent in the first hours and can continue for months, always below the magnitude of the main event.
Data from 10/16/26, 6:58 AM UTC
- U.S. Geological Survey — Earthquake Hazards ProgramLicence: Domínio público (U.S. Public Domain) · Credit: U.S. Geological Survey (USGS)
- GeoNames cities15000Licence: CC BY 4.0 · Credit: Dados de cidades: GeoNames (CC BY 4.0)
- Dados de cidades: GeoNames (CC BY 4.0)
How to read these numbers
The query uses a coordinate box around San Francisco Bay Area, shown at the end of the page. The list can therefore include an event just across the border or offshore, which is useful: a strong quake a hundred kilometres out to sea is still felt on land.
Frequently asked questions
- Was there an earthquake in San Francisco Bay Area today?
- If the first row carries today’s date, yes. When there is no recent event, the table shows earlier quakes from the queried period so you have a reference.
- Why are small quakes listed here?
- Where the seismic network is dense, the catalogue records low magnitudes that nobody feels. That makes a well monitored region look more active than one with few stations.