How to Build a California Earthquake Go-Bag That Emergency Officials Actually Recommend
What should I put in an earthquake go-bag in California?
California emergency officials recommend at minimum one gallon of water per person per day for 72 hours, non-perishable food, a first-aid kit, a battery or hand-crank NOAA radio, a flashlight with extra batteries, copies of important documents, cash in small bills, a whistle, and any personal medications or medical supplies. Cal OES publishes a full checklist at caloes.ca.gov.
What's the correct thing to do during an earthquake?
Drop to the ground, take Cover under a sturdy table or desk, and Hold On until shaking stops. If nothing is nearby, cover your head and neck with your arms. Stay away from windows and exterior walls. Do not run outside while shaking is happening. The old advice about standing in a doorway is outdated and no longer recommended by USGS or Cal OES.
How does ShakeAlert work in California and how do I get earthquake warnings on my phone?
ShakeAlert is a USGS earthquake early warning system that detects the first seismic waves from an earthquake and sends alerts before stronger shaking arrives. In California, alerts can reach compatible smartphones through Wireless Emergency Alerts if your phone settings allow it. The MyShake app, developed by UC Berkeley, also delivers ShakeAlert notifications. Check your phone's emergency alert settings to confirm you're enrolled.
How much water should I store for an earthquake emergency?
FEMA and Cal OES recommend storing at least one gallon of water per person per day for a minimum of 72 hours, though California emergency managers increasingly suggest aiming for up to two weeks given how long infrastructure disruptions can last after a major event. Don't forget water for pets. Store water in sealed, food-grade containers and replace it periodically per the container manufacturer's guidance.
How soon after a major earthquake can I go back inside my home?
You should not re-enter a building that has visible structural damage until it has been inspected and cleared by local authorities or a licensed structural inspector. After a major earthquake, cities and counties typically deploy rapid-assessment teams that tag buildings as safe (green), restricted entry (yellow) or unsafe (red). Follow posted placards and official instructions from your local emergency management office.
- USGS Live Earthquake Map — real-time magnitude, depth, and aftershock tracking
- MyShake Early Warning App — California's free earthquake early-warning app
- Cal OES Earthquake Preparedness — official state guidance on what to do before, during, and after
California averages several thousand earthquakes a year, most too small to feel. The ones that aren't can knock out power, water and cell service within seconds, leaving you on your own for 72 hours or longer before emergency services can reach you. What's in your bag when that happens matters more than most people expect.
Related: How to Build a California Go-Bag That Emergency Officials Actually Recommend · How to Build a California Earthquake Go-Bag: What Cal OES and USGS Actually Recommend
The Core Supply List
Cal OES and FEMA both recommend building a go-bag around a 72-hour minimum, though California emergency managers increasingly suggest planning for up to two weeks if you're in an area where infrastructure is likely to be disrupted. The fundamentals: one gallon of water per person per day (don't forget pets), enough non-perishable food to match your water supply, and a manual can opener. Prepackaged emergency food bars work, but so does a thoughtful rotation of canned goods you already buy.
Beyond food and water, the list that Cal OES publishes at caloes.ca.gov emphasizes a battery-powered or hand-crank NOAA weather radio, copies of critical documents (ID, insurance cards, prescriptions, a list of emergency contacts written on paper, not just stored in your phone), a first-aid kit with any personal medications, flashlights with extra batteries, and a whistle to signal for help. Cash in small bills matters: ATMs and card readers don't work without power.
If you have specific medical needs, build around them first. That means extra prescription medications if you can get a 30-day emergency supply from your doctor or pharmacist, hearing aids with backup batteries, backup eyeglasses, an asthma inhaler. California's Medical Baseline program, administered through your utility, can help households with serious medical needs get priority restoration notices, though you'd need to have enrolled before an event.
What to Do During an Earthquake
USGS and Cal OES guidance is consistent on this: Drop, Cover and Hold On. Get under a sturdy desk or table, cover your head and neck with your arms if nothing's nearby, and stay away from windows, exterior walls and anything that can fall. Do not run outside during shaking. The old advice about doorways is outdated and wrong; a table offers better protection.
If you're in bed, stay there and cover your head with a pillow. If you're outdoors, move away from buildings, streetlights and utility lines and drop to the ground. If you're driving, pull over away from overpasses, bridges, power lines and buildings, stay inside the vehicle, and proceed cautiously after shaking stops.
California and parts of the Pacific Northwest use the ShakeAlert earthquake early warning system, operated by USGS in partnership with Cal OES. If your phone is running a compatible app such as MyShake (developed by UC Berkeley Seismological Laboratory) or if you have Wireless Emergency Alerts enabled in your phone's settings, you may receive a few seconds of warning before shaking reaches you. A few seconds is enough to drop and take cover or pull off the road. ShakeAlert delivery through WEA became available to California smartphone users in recent years, but whether your device receives it depends on carrier support and your phone's settings, so it's worth verifying yours are on.
What to Do Immediately After
Expect aftershocks. Some of them will be strong. After the initial shaking stops, check yourself and others for injuries before moving. If you smell gas, leave the building, leave the door open, don't use any electrical switches or open flames, and call your gas company or 911 from outside. Don't re-enter a building that has visible structural damage until it's been inspected.
Tap water may be unsafe after a major event due to broken mains or treatment-plant failures. Use your stored water until local authorities confirm the supply is safe. If the power is out, keep your refrigerator and freezer doors closed to extend food safety; the FDA's general guidance is that a full freezer stays safe for about 48 hours if the door stays shut.
See also: California Earthquake Go-Bag Checklist: What Emergency Officials Actually Say to Pack · Your California Go-Bag Checklist: What Emergency Officials Actually Recommend You Pack
Check in with your household's designated out-of-area contact. Text rather than call when cell networks are congested; texts often get through when voice calls don't. Tune to a local AM radio station or your NOAA radio for official updates. Do not post or share unverified information about which roads are open or where shelters are located.
How to Get Your Household Ready Before the Next One
Assembling a go-bag is the starting point, not the finish line. Cal OES recommends identifying the safest spots in every room of your home before an event, and practicing Drop, Cover and Hold On with everyone in your household so it's a reflex, not a decision you're making while the ground is moving.
Strap water heaters, bookshelves and large appliances to wall studs. Relocate heavy items from high shelves to lower ones. Know where your home's gas shutoff is and have the right wrench accessible, though Cal OES advises against turning the gas off unless you actually smell gas or suspect a leak: once it's off, only your gas utility should turn it back on, and restoration after a major event can take days.
If you haven't signed up for your county's emergency alert system, that's a separate but equally important step. Most California counties operate through AlertCalifornia or a county-run system; your county's Office of Emergency Services website is the right place to register your cell number for local alerts, since county-level alerts go beyond what Wireless Emergency Alerts automatically push to phones. Cal OES maintains a directory of county alert systems at caloes.ca.gov.
This is general information, not emergency, medical or legal advice. For current official guidance on earthquake preparedness, go-bag recommendations and ShakeAlert, check Cal OES at caloes.ca.gov and USGS ShakeAlert information at earthquake.usgs.gov/ShakeAlert. County-specific alert enrollment and local emergency instructions are available through your county's Office of Emergency Services.