Rolling Blackouts: What to Do and How Long They Last

If your power goes out, check your utility’s outage map and alerts, note the start time, and keep refrigerator and freezer doors closed. Do not wait for an estimated restoration time if essential medical equipment or unsafe indoor temperatures require you to leave.

Rolling blackouts—also called rotating outages—are deliberate, controlled power cuts that move between groups of customers. They reduce electricity demand during a grid emergency to help prevent a wider, longer outage. Your utility, not your household breaker, controls the rotation. Southern California Edison explains the process.

How long do rolling blackouts last?

There is no universal duration or guaranteed household schedule. Use your own utility’s instructions rather than a nationwide estimate.

For example, Southern California Edison says its California grid-operator-mandated rotating outages last approximately one hour, depending on circumstances. It also warns that it may have as little as 10 minutes before starting cuts—too little time to notify every affected customer individually. A conservation alert alone does not mean an outage will occur. SCE rotating-outage guidance

Look up your address and, where applicable, your outage group or circuit number. SCE customers can find their group on their bill or through its outage map. A neighbor across the street can remain powered because circuits do not necessarily follow neighborhood boundaries. SCE outage-group guidance

If your outage continues beyond the utility’s expected window, check again and report it as instructed. Do not assume every outage during a grid emergency is part of the rotation: storm damage can leave customers without electricity even after controlled cuts end, as Oncor documented on February 18, 2021.

Protect food through repeated cuts

These limits assume the appliance was properly cold before the outage and doors stay closed. CDC food-safety guidance

Cold storage	Time without power	What to do
Refrigerator	Up to 4 hours	Keep closed; prepare a cooler with ice if the outage continues.
Full freezer	Approximately 48 hours	Keep closed; check food when power returns.
Half-full freezer	Approximately 24 hours	Keep closed; check food when power returns.

CDC recommends moving refrigerated perishables to an iced cooler at the four-hour point, keeping them at 40°F or below. Discard refrigerated perishables after four hours without power or another cold source. CDC guidance

A brief return of electricity is not proof that food has cooled back down. During repeated cuts, record outage periods and check temperatures rather than treating every restoration as a fresh four-hour allowance. FoodSafety.gov’s chart says to discard foods such as meat, milk and eggs held at 40°F or above for more than two hours. Frozen-food decisions depend on the item, remaining ice crystals and temperature; use the item-by-item food chart. Never taste food to test its safety.

Reduce immediate household risks

• Medical needs: Follow your provider’s outage plan for powered devices and refrigerated medicines, as Ready.gov recommends. Do not assume utility medical registration guarantees uninterrupted service—SCE expressly says it cannot. For planning, size battery backup around essential loads and runtime.
• Heat or cold: Go to an open community location with power if conditions become extreme; check local officials for heating or cooling locations. Never heat your home with a gas stove or oven. Ready.gov outage guidance
• Appliances: Turn off or disconnect nonessential appliances and electronics; leave one light on to show when power returns. This helps prevent unexpected restarts and overloaded circuits at restoration. SCE safety steps
• Portable generators: Never operate one in a home or garage, even with doors and windows open. CDC says to run it outdoors more than 20 feet from windows, doors and vents, with battery-powered or battery-backup CO detection inside. CDC generator precautions

Last reviewed: October 11, 2026. This is general preparedness guidance, not a live outage notice; follow your utility and local emergency authorities.