Did you feel that? If you're in the Bay Area, you probably just looked at your ceiling fan or waited for the second jolt. Dealing with an earthquake just now in San Francisco is basically a local rite of passage, but it never stops being a little unnerving.
Earlier this morning, Saturday, January 17, 2026, a series of tremors rattled parts of Northern California. While the biggest activity was centered a bit south of the city, the ripples were definitely felt across the Peninsula. According to the USGS, a magnitude 3.3 earthquake struck at 5:53 AM PST near Ridgemark, followed by a smaller 3.0 magnitude quake in the East Foothills.
It wasn't a "big one." Not even close. But for a Saturday morning wake-up call, it did the job.
The Specifics of the Recent Shaking
The USGS (United States Geological Survey) tracks these things down to the millisecond. The 3.3 magnitude event occurred at a depth of about 7.2 kilometers. That’s relatively shallow. Shallow quakes often feel sharper and more "jolty" than deeper ones, even if the magnitude is low.
Honestly, most people in high-rises in San Francisco probably felt a gentle sway. If you were in a single-family home on bedrock, you might have missed it entirely.
Why the East Bay Felt It Differently
The East Foothills tremor, which also clocked in around a 3.0 magnitude, happened just a few hours later. We've seen a lot of "swarm" activity lately. Just yesterday, January 16, a 3.0 magnitude quake hit near Alum Rock at 6:54 AM.
It’s like the earth is stretching its legs.
Seismologists like Amanda Thomas from UC Davis have been pointing out that these tiny swarms are actually incredibly useful. They help researchers map out hidden fault fragments that aren't visible on the surface. Specifically, new research published just this week in Science suggests there's a complex "captured slab fragment" beneath Northern California that moves in ways we didn't fully understand until now.
Is This "Earthquake Weather"?
Let's address the myth right now. There is no such thing as earthquake weather.
👉 See also: Layla, Michael, and Camille: The Ocklawaha Case and What Really Happened
You've heard it before—it’s hot, it’s still, "feels like a quake's coming." Science doesn't back that up. Earthquakes happen miles underground, completely indifferent to whether it's raining or 90 degrees in the Mission.
The real factor is the San Andreas Fault and its many cousins, like the Hayward and Calaveras faults. The Bay Area is basically a jigsaw puzzle of tectonic plates trying to slide past each other.
Sometimes they get stuck.
Then they snap.
What You Should Have Done (and Should Do Next Time)
When an earthquake just now in San Francisco happens, the instinct is to run outside. Don't.
Unless you're in a very old, unreinforced masonry building, the most dangerous place to be is near the exterior walls where glass and facades can fall on you.
- Drop, Cover, and Hold On: This isn't just a school drill mantra. It works. Get under a sturdy table.
- Check Your Gas: If you smell rotten eggs after a larger shake, turn off the main gas valve.
- Don't Call 911 for Info: Only call if there’s a real emergency. Use the USGS "Did You Feel It?" website to report your experience; it actually helps scientists map the intensity.
The "Hidden" Faults No One Talks About
We all know the San Andreas. It’s the celebrity of faults. But the recent activity near Alum Rock and Ridgemark highlights the importance of the Calaveras and Hayward systems.
These faults run right through heavily populated areas. The Hayward Fault, in particular, is often called a "tectonic time bomb" by experts because it’s overdue for a major rupture. A 3.0 or 3.3 magnitude quake is a reminder, a little nudge to check your emergency kit.
Speaking of kits, when was the last time you swapped out the water in yours? If it’s been more than six months, it’s probably tasting like plastic.
Actionable Next Steps
Since you just experienced (or slept through) a tremor, use that adrenaline for something productive.
- Secure Your Heavy Stuff: Check your bookshelves and TVs. If they aren't strapped to the wall, a magnitude 6.0 will turn them into projectiles.
- Download MyShake: This app, developed by UC Berkeley, can give you a few seconds of warning before the shaking starts. It’s not much, but it’s enough to get under a table.
- Update Your Contact Plan: In a real emergency, local cell towers get jammed. Texting often works when calls don't. Pick an out-of-state relative as a central "check-in" person for your whole family.
- Review Your Insurance: Standard homeowners insurance doesn't cover earthquakes. Look into the California Earthquake Authority (CEA) if you're worried about structural damage.
The shaking has stopped for now, but in San Francisco, the ground is always moving—even when we can't feel it. Keep your shoes under the bed and your flashlight batteries fresh.