Why outages last minutes in some cases and days in others, what causes them, why 72 hours is the planning standard, and how to check your utility.
- Local faults are often quick; major storms can mean multi-day outages.
- 72 hours is a planning standard, not a prediction.
- Save your utility's outage map and sign up for alerts now.
There is no single answer to how long an outage will last. Some are over before you finish resetting the clocks. Others, after major storms, can stretch to several days. This guide explains what drives the difference, so you can plan sensibly without guessing at numbers.
Short outages
Brief outages often come from a momentary fault on a line, a tripped protective device, a small animal contacting equipment, or a vehicle hitting a pole. Equipment sometimes resets itself automatically, and many of these end in seconds or minutes. A single local fault is usually quick for a crew to locate and fix, though some take a few hours.
Longer outages
Outages last longer when the damage is physical and widespread, or when crews cannot safely get to the site. Common causes include:
- Heavy wind, which brings down trees and lines
- Ice and snow loading (see our ice storm guide)
- Flooding, which can damage equipment and block access
- Hurricanes and tornadoes (see hurricane power outage checklist)
- Wildfires, which can damage equipment and force shutdowns for safety
- Equipment failure or planned maintenance
- Heat waves, where heavy demand can strain the system
Why major storms take days
After a big storm, crews must first make the area safe, then restore the facilities that serve the most people, such as transmission lines and substations, and hospitals and other critical services. Then they work outward through neighbourhood lines, and finally to individual service connections. Your home may be near the end of that queue even if the neighbourhood next door is back. Crews may also need to wait for winds to ease or for roads to be cleared before they can work. Utilities from other regions may help, and that takes time to arrange.
Why plan for 72 hours
Government guidance in both Canada and the US says households should be prepared to look after themselves for at least 72 hours (three days). It is not a prediction that your outage will last that long. It is a sensible target: long enough to cover most outages, and short enough to be affordable to prepare for. Many people go beyond it. See our 72-hour checklist, and if you want to go further, our 90-day preparedness plan.
How to check your utility
Most utilities offer an outage map or status page, a phone line, and often text or app alerts. Do this before you need it:
- Find your utility's name on your bill.
- Save its outage reporting number and website in your phone.
- Sign up for text or app alerts.
- Look for the outage map and bookmark it.
- Note whether you can report an outage online or by text.
Our alerts and outage reporting guide walks through this.
What to do with this information
Use it to set expectations. If you lose power during a storm, assume it could be a long one and take protective steps early: close the fridge, charge devices, and start your plan. If power returns quickly, you lose nothing. Use the outage planner to work out what you would need for your household, and the readiness score to see where you stand. For the basics of getting ready, read how to prepare for a power outage.
Prepare for the range, not the average
Because outages vary so widely, the smart approach is to prepare for a short one comfortably and a long one safely. Start with water, light, a radio and no-cook food, then add backup power and heat if your climate demands it. If you depend on medical equipment, plan for longer and speak to your care team. A small amount of preparation covers the common cases, and extra layers cover the rare ones.
Quick answers
Can my utility tell me exactly when power will return?
Not always. Estimated restoration times are best guesses and may change as crews assess damage.
Why is my neighbour's power back but not mine?
Homes can be on different lines or transformers. Crews restore the larger shared equipment first, and smaller local faults later. Report your outage separately.