A Tornado Warning in Canada means a tornado is occurring or expected to occur and people in the affected area should take immediate action to protect themselves.
Tornadoes can produce extremely strong winds, flying debris and severe damage to buildings, vehicles, trees and infrastructure. Conditions can develop and change rapidly, leaving people with limited time to reach a safe location.
Environment and Climate Change Canada issues Tornado Warnings when a tornado threat is occurring or expected. Under Canada’s colour-coded weather alert system, Tornado Warnings can appear as Yellow, Orange or Red alerts depending on the potential risk.
The seriousness of a tornado event depends on factors such as the strength of the tornado, location, population exposure, duration and expected impacts.
This guide explains what a Tornado Warning means in Canada, why one may be issued, how serious tornadoes can become, what Yellow, Orange and Red alerts mean and what to do when a Tornado Warning affects your area.
What Is a Tornado Warning?
A Tornado Warning is an urgent weather alert issued when a tornado is occurring or expected to occur.
Environment and Climate Change Canada issues warnings when severe weather is happening or expected to happen. Warnings provide information about the expected conditions, potential impacts, affected locations and actions people should take.
A Tornado Warning indicates a more immediate threat than a Tornado Watch.
People in the affected area should take the warning seriously and move to a safe location.
Tornadoes can develop rapidly and may be difficult to see because of darkness, heavy rainfall or surrounding terrain.
You can learn more about Tornado Warnings and other weather alerts in Canada.
Why Is a Tornado Warning Issued?
A Tornado Warning is issued to alert people when a tornado is occurring or expected to occur.
The warning gives people potentially life-saving information and an opportunity to move to a safer location.
Several factors can influence the seriousness of a tornado event.
Strong Winds
Tornadoes can produce extremely powerful and destructive winds.
Strong winds may damage or destroy buildings, uproot trees, overturn vehicles and damage utility infrastructure.
The severity of the damage depends on the strength of the tornado and the structures and communities in its path.
Flying Debris
Flying debris is one of the most dangerous hazards associated with tornadoes.
Strong winds can lift and carry branches, building materials and other objects through the air.
Debris can cause serious injuries and additional damage to buildings and vehicles.
Rapid Development
Tornadoes can develop quickly.
Weather conditions may change over a relatively short period, leaving people with limited time to respond.
For this reason, people should monitor current weather information when severe thunderstorms and tornadoes are possible.
Location
The impacts of a tornado depend significantly on where it occurs.
A tornado moving through a populated community may cause more significant impacts than a similar tornado occurring in a remote area.
Buildings, infrastructure, population density and access to shelter can all influence the seriousness of the event.
Duration and Path
Some tornadoes remain on the ground for a relatively short period, while others may travel considerable distances.
A longer or wider tornado path may expose more people, buildings and infrastructure to dangerous conditions.
The Government of Canada provides additional information about tornadoes and tornado safety, including where tornadoes occur and how people can protect themselves.
How Serious Is a Tornado Warning?
A Tornado Warning should always be taken seriously because tornadoes can create life-threatening conditions and cause significant damage.
Possible impacts may include:
- Extremely strong winds
- Flying debris
- Damage to homes and buildings
- Roof damage
- Destroyed structures
- Uprooted trees
- Overturned vehicles
- Downed power lines
- Power outages
- Blocked roads
- Transportation disruptions
- Damage to critical infrastructure
- Serious injuries
- Loss of life
The seriousness of a tornado event depends on factors such as tornado strength, path, duration, location and the number of people and structures exposed.
Even a relatively short-lived tornado can cause serious damage.
Environment and Climate Change Canada uses Weather Impact Guides to assess how hazardous weather may affect daily life, travel, utilities and services, land and structures, human health and community recovery.
Tornado Warning Colours in Canada
Tornado Warnings in Canada can appear as Yellow, Orange or Red alerts.
The colours move from Yellow to Orange to Red as the potential risk increases.
The colour assigned to a Tornado Warning is not determined solely by the expected strength of the tornado.
Environment and Climate Change Canada considers both the expected impacts of the weather event and confidence in the forecast when selecting an alert colour.
Yellow Warning – Tornado
A Yellow Warning – Tornado indicates hazardous weather that may cause damage, disruption or health impacts.
Environment and Climate Change Canada describes the expected impacts of Yellow alerts as generally moderate, localized and/or short-term.
During a Yellow Warning – Tornado, a tornado threat may create dangerous conditions and potentially cause property damage, transportation disruptions and risks to human safety.
Although Yellow represents the lowest of Canada’s three alert colours, any Tornado Warning should be taken seriously.
People in affected areas should immediately follow the safety information included in the warning and move to a safe location.
Orange Warning – Tornado
An Orange Warning – Tornado indicates a greater level of potential risk than a Yellow alert.
Orange alerts indicate severe weather that is likely to cause significant damage, disruption or health impacts.
The expected impacts may be major, widespread and/or last for several days.
During an Orange Warning – Tornado, dangerous weather may cause significant property damage, widespread utility outages, transportation disruptions and serious risks to people in the affected area.
People should immediately move to a safe location and follow official information and instructions from local authorities.
Red Warning – Tornado
A Red Warning – Tornado represents the highest level of potential risk within Canada’s colour-coded weather alert system.
Red alerts indicate very dangerous and possibly life-threatening weather that is expected to cause extreme damage and disruption.
The expected impacts may be extensive, widespread and prolonged.
During a Red Warning – Tornado, an exceptionally dangerous tornado event may cause extensive destruction, major infrastructure damage, widespread utility outages and an extreme risk to life and safety.
Red alerts are rare and communicate the most serious potential weather risk within Canada’s alert system.
People in affected areas should immediately take protective action and follow all instructions from emergency officials.
Environment and Climate Change Canada provides additional information about Yellow, Orange and Red weather alerts and how the colours communicate increasing levels of potential risk.
Yellow vs Orange vs Red Tornado Warnings
The main difference between Yellow, Orange and Red Tornado Warnings is the level of potential risk communicated by the alert colour.
A Yellow warning indicates hazardous weather that may cause moderate, localized or short-term impacts.
An Orange warning indicates severe weather that is likely to cause significant impacts that may be major, widespread or prolonged.
A Red warning indicates very dangerous and potentially life-threatening weather that is expected to cause extreme impacts that may be extensive, widespread and prolonged.
| Alert colour | General meaning | Potential tornado impacts |
|---|---|---|
| Yellow | Moderate, localized or short-term impacts | Dangerous conditions, localized damage and risks to safety |
| Orange | Major, widespread or prolonged impacts | Significant damage, major disruption and serious risks to safety |
| Red | Extreme, widespread and prolonged impacts | Extensive destruction, severe disruption and extreme danger to life |
The warning colour is selected using both expected impacts and forecast confidence.
Environment and Climate Change Canada’s Alert Colour Matrix explains how forecasters combine expected impacts and forecast confidence when selecting Yellow, Orange or Red.
Can the Colour of a Tornado Warning Change?
The colour assigned to a Tornado Warning reflects the potential risk associated with the expected event.
Environment and Climate Change Canada considers expected weather impacts and forecast confidence when selecting alert colours.
Tornado conditions, expected impacts and forecast confidence may change as severe weather develops and new information becomes available.
For this reason, people should continue monitoring the latest Tornado Warning rather than relying only on an earlier alert.
Always read the complete warning because it may include updated information about the tornado threat, affected locations, expected impacts and recommended actions.
Tornado Warning vs Tornado Watch
A Tornado Warning and Tornado Watch communicate different levels of certainty and urgency.
A Tornado Watch means conditions are favourable for tornadoes to develop.
A Tornado Warning means a tornado is occurring or expected to occur.
A Watch gives people advance notice that they should monitor changing conditions and be prepared to take action.
A Warning indicates a more immediate threat.
People in the affected area should take appropriate protective action and follow the safety information included in the warning.
Tornado Warning vs Severe Thunderstorm Warning
A Tornado Warning and Severe Thunderstorm Warning are both urgent weather alerts, but they communicate different hazards.
A Severe Thunderstorm Warning indicates a severe thunderstorm is happening or expected and may produce damaging winds, large hail or heavy rainfall.
A Tornado Warning indicates a tornado is occurring or expected to occur.
Some severe thunderstorms can produce tornadoes.
When a tornado threat develops during a severe thunderstorm, Environment and Climate Change Canada may issue a Tornado Warning for the affected area.
What Can Happen During a Tornado Warning?
The impacts of a Tornado Warning depend on the strength, duration, path and location of the tornado.
Extreme Winds
Tornadoes can produce powerful winds capable of causing significant damage.
Buildings may lose roofs or walls, while weaker structures may be severely damaged or destroyed.
Flying Debris
Strong winds can carry objects through the air.
Flying debris can damage buildings and vehicles and cause serious or fatal injuries.
Damage to Buildings
Homes, businesses and other structures may be damaged or destroyed.
The severity of the damage depends on the strength of the tornado and the construction of the affected buildings.
Uprooted Trees
Tornadoes may uproot trees or break large branches.
Falling trees can damage homes, vehicles, roads and power lines.
Power Outages
Tornadoes can damage utility poles, power lines and other electrical infrastructure.
Power outages may continue after the tornado has ended while repairs are completed.
Transportation Disruptions
Fallen trees, debris, damaged roads and utility lines may block transportation routes.
Road closures and disruptions may continue during cleanup and recovery.
Injuries and Loss of Life
Tornadoes can cause serious injuries and deaths.
Moving to an appropriate shelter as quickly as possible can reduce exposure to dangerous winds and flying debris.
What Should You Do During a Tornado Warning?
A Tornado Warning requires immediate attention.
People in the affected area should follow the safety information included in the warning and move to an appropriate shelter.
Go Indoors
Move inside a sturdy building as quickly as possible.
Do not remain outdoors to watch or photograph the tornado.
Move to the Lowest Level
Go to the lowest level of the building, preferably a basement.
If a basement is unavailable, move to a small interior room or hallway on the lowest floor.
Stay Away From Windows
Avoid windows, skylights and exterior doors.
Strong winds and flying debris can break glass and create additional hazards.
Put as Many Walls Between You and the Outside as Possible
Move toward the centre of the building.
Interior rooms, hallways and stairwells may provide additional protection from wind and debris.
Protect Your Head
Use your arms or available objects to protect your head and neck from flying or falling debris.
Leave Mobile Homes and Temporary Structures
Mobile homes and temporary structures may provide limited protection from tornadoes.
Move to a sturdy shelter when it is safe and possible to do so.
Monitor Official Information
Continue monitoring weather alerts and instructions from local authorities.
Environment and Climate Change Canada provides official weather radar and satellite services that can help people monitor severe weather.
The Government of Canada also provides guidance on how to prepare for tornadoes.
What Should You Do If You Are Driving During a Tornado Warning?
Driving during a Tornado Warning can be extremely dangerous.
If a Tornado Warning affects your location or travel route, seek appropriate shelter when it is safe to do so.
Do not attempt to outrun a tornado in your vehicle.
Tornadoes may change direction, and roads can become blocked by traffic, debris or damaged infrastructure.
Follow the safety information included in the warning and instructions from local authorities.
How Long Does a Tornado Warning Last?
There is no standard duration for a Tornado Warning.
The length of the warning depends on the development, movement and duration of the tornado threat.
Some tornado threats may affect an area for a relatively short period, while severe weather systems may continue producing tornado risks for longer periods.
Conditions can change rapidly.
Continue monitoring current weather information until the warning ends and authorities indicate the immediate threat has passed.
Where Do Tornadoes Occur in Canada?
Tornadoes can occur in several regions of Canada.
Environment and Climate Change Canada identifies parts of the Prairies, southern Ontario and southern Quebec as regions where tornadoes occur most frequently.
Tornadoes can also occur in other parts of the country when atmospheric conditions support their development.
The frequency, strength and impacts of tornadoes vary by region and year.
When Is Tornado Season in Canada?
Tornadoes can occur at different times of the year depending on the region and weather conditions.
Most Canadian tornadoes occur between late spring and early fall.
The greatest tornado activity generally occurs during the warmer months when atmospheric conditions are more favourable for severe thunderstorms.
However, people should monitor official weather information whenever severe thunderstorms and tornadoes are possible.
How Are Tornadoes Rated in Canada?
Tornadoes in Canada are rated using the Enhanced Fujita Scale.
The scale ranges from EF0 to EF5.
Tornado ratings are assigned based on observed damage and estimated wind speeds.
| Rating | General classification |
| EF0 | Weakest rating |
| EF1 | Moderate damage potential |
| EF2 | Considerable damage potential |
| EF3 | Severe damage potential |
| EF4 | Devastating damage potential |
| EF5 | Highest rating |
The strength rating of a tornado is different from the colour assigned to a Tornado Warning.
The Enhanced Fujita rating describes the tornado based on damage after the event, while the Yellow, Orange or Red warning colour communicates potential risk when the alert is issued.
How Can You Check Current Tornado Warnings?
Current Tornado Warnings and other weather alerts can be checked through Environment and Climate Change Canada’s official weather services.
The Weather Information map allows users to view current alert areas and read the complete alert text for affected locations.
You can use the official Weather Information map to check current forecasts and alerts across Canada.
The WeatherCAN application also provides official forecasts, alerts and customizable notifications.
Frequently Asked Questions About Tornado Warnings
A Tornado Warning means a tornado is occurring or expected to occur. People in the affected area should take immediate action to protect themselves.
A Tornado Warning should always be taken seriously because tornadoes can produce life-threatening winds, flying debris and significant damage.
A Yellow Warning – Tornado indicates hazardous weather that may cause moderate, localized or short-term impacts. Any Tornado Warning should be treated seriously.
An Orange Warning – Tornado indicates severe weather that is likely to cause significant impacts, major disruption and serious risks to safety.
A Red Warning – Tornado represents the highest alert colour and indicates very dangerous and potentially life-threatening weather expected to cause extreme impacts.
A Tornado Watch means conditions are favourable for tornadoes to develop. A Tornado Warning means a tornado is occurring or expected to occur.
When available, a basement can provide protection during a tornado. Otherwise, move to a small interior room or hallway on the lowest floor and stay away from windows.
Parts of the Prairies, southern Ontario and southern Quebec are among the Canadian regions where tornadoes occur most frequently, although tornadoes can occur elsewhere.
Sources
- https://www.canada.ca/en/services/environment/weather/severeweather/weather-alerts.html
- https://www.canada.ca/en/environment-climate-change/services/seasonal-weather-hazards/warm-season-weather-hazards/tornadoes.html
- https://www.canada.ca/en/services/environment/weather/severeweather/weather-alerts/weather-impact-guides.html
- https://www.canada.ca/en/services/environment/weather/severeweather/weather-alerts/colour-coded-alerts.html
- https://www.canada.ca/en/services/environment/weather/severeweather/weather-alerts/choose-alert-colours.html
- https://www.canada.ca/en/services/environment/weather/radar-satellites.html
- https://www.canada.ca/en/services/policing/emergencies/preparedness/get-prepared/hazards-emergencies/tornadoes/how-prepare.html
- https://www.canada.ca/en/environment-climate-change/services/weather-general-tools-resources/weather-webmapping.html
- https://www.canada.ca/en/environment-climate-change/services/weather-general-tools-resources/weathercan.html