What Every Home Needs for an Extended Power Outage

Emergency preparedness advice has long centered on a simple metric: Keep enough food, water, and other necessities on hand to last three days.

But for an extended power outage, that may no longer be enough.

“A three-day emergency kit is still a good starting point, but I’d consider it the minimum rather than the actual goal,” says Brian Armentrout of Chariot Energy. “In Texas, we’ve seen severe weather events where power outages and other disruptions can last well beyond 72 hours.”

It’s not just a Texas problem. Close to 375,000 customers lost power after severe storms tore through Northwest Indiana earlier this month. While most had electricity restored within days, some were still waiting nearly two weeks later.

In January, a historic ice storm knocked out power to more than 330,000 customers across Mississippi and Louisiana. Again, while most had power restored within days, some waited closer to the two-week mark for service to return.

But preparing for that type of emergency requires more than just accurately estimating how long you'll be waiting for the power to come back on. It also also means thinking through what your household needs if the systems you normally take for granted don’t come back tomorrow—or the days after that.

How long should you prepare for a power outage?

The familiar three-day kit is still a vital part of emergency preparedness, but the American Red Cross recommends that amount for an evacuation kit.

For households sheltering at home, the recommendation is much longer: two weeks of food and water.

Refrigerated perishable food may need to be discarded after four hours without power. (Scott Olson/Getty Images)

Daniel Kilburn, an emergency-planning consultant and retired U.S. Army senior infantry drill sergeant, makes a similar distinction.

“The three-day emergency kit is still good if you're actually evacuating. It should not take more than three days to get to where you need to go,” he says. “However, based on current power outages happening around the country, eight to 10 days is not unreasonable."

But most households aren't prepared for that: 69% of respondents said they had assembled emergency supplies, according to the Federal Emergency Management Agency's latest National Household Survey. Among that group, just 34% said their supplies could last more than two weeks.

How much water and food do you need?

Kilburn recommends having enough food and water for every member of the household to last a full two weeks. But that doesn't mean buying two weeks of emergency supplies all at once.

Instead, he recommends gradually adding extra shelf-stable foods and water during normal shopping trips, then rotating those foods through the kitchen so the emergency supply functions more like a well-stocked pantry.

Water is the first priority.

“Water is one of the biggest things people tend to overlook,” Armentrout says. “During an extended outage, water service can also be disrupted, so it’s important to have enough bottled water on hand for drinking and basic needs.”

Fuel for generators and vehicles can also be vital to store in the case of an extended blackout. (Go Nakamura/Getty Images)

Winter Storm Uri showed how those failures can overlap. The 2021 storm caused power losses for 69% of Texans and water service disruptions for 49%, according to the Texas State Auditor's Office.

The Red Cross recommends one gallon of water per person per day. For a family of four, that works out to 12 gallons for three days—or 56 gallons for two weeks.

And while food may be more intuitive to store than water, it presents a different problem: How to cook it without power.

A closed refrigerator generally keeps food cold for only about four hours without power, according to FoodSafety.gov. A full freezer can maintain its temperature for about 48 hours; a half-full freezer, about 24 hours.

That makes shelf-stable foods a good choice. But Kilburn warns that households should also have a safe way to boil water or prepare food if the power stays out.

What will still work when the power goes out?

A cellphone may become one of the most useful tools in a blackout, and useless within hours without a way to recharge it.

“Backup power is another area people often underestimate,” Armentrout says. “A portable battery bank, generator, or small solar charger can help keep phones and other essential devices operating when the power is out for several days.”

The Red Cross also recommends a battery-powered or hand-crank radio, backup batteries and chargers, and a paper copy of important phone numbers.

But phones are only one electrical dependency inside a modern home. Kilburn recommends mentally walking through an ordinary day and asking what stops working without electricity.

“Let's say you decide it's time to evacuate and your car is in the garage, how are you going to get the garage door open?” he says.

Medical equipment is also a vital consideration. More than 3 million Medicare beneficiaries rely on electricity-dependent durable medical and assistive equipment, according to the Department of Health and Human Services.

For these households, the Red Cross recommends establishing a backup plan in advance.

Generators can provide backup power, but they carry their own risks: carbon-monoxide poisoning from misuse. Nearly 100 Americans die each year in poisonings caused by portable generators, according to the U.S. Consumer Product Safety Commission.

To stay safe, never operate a generator in an enclosed space like your home or garage—even with doors or windows open. Keep them outdoors and more than 20 feet from windows, doors, and vents, and make sure you also have a battery-powered or battery-backup carbon-monoxide detector.

How to stay safe in extreme heat

Eventually, the biggest question during a prolonged outage may not be how many supplies remain, but whether the home itself is still safe.

“Before an outage, close blinds or blackout curtains to reduce the amount of heat coming into the house,” Armentrout says. “If the power goes out, stay in the coolest part of the home, which is typically a room on the lower floor away from direct sunlight.”

Battery-powered fans can help, but only to a point. The Centers for Disease Control says fans should be used indoors only when temperatures are below 90 degrees Fahrenheit. Above that, using a fan can actually increase body temperature.

That means one of the most important parts of a blackout plan can't be stored in a closet: somewhere else to go.

Kilburn recommends finding out in advance where cooling centers would operate during a major outage. And Armentrout says households should establish their threshold for leaving before conditions deteriorate.

“It becomes unsafe when your home can no longer meet your basic needs,” he says. “That could be caused by a variety of things, from temperatures becoming too hot or too cold, to running low on water, necessary medications, or having the ability to run critical medical equipment.”

So preparing for two weeks without electricity doesn't mean planning to stay inside a powerless home for two weeks no matter what.

It means having enough food, water, and backup power to preserve your options—and a plan for where to go when staying home is no longer one of them.