Thunderstorms, Lightning & Tornado Safety

Severe weather, including thunderstorms and tornadoes, can develop quickly in Ontario. Understanding how warnings are issued, what they mean, and how to respond is essential for your safety.

Lightning & Thunderstorm Safety

Thunderstorms can bring lightning, heavy rain, strong winds, and hail. Lightning can strike without warning and poses a significant risk on campus. If you hear thunder, you are close enough to be struck by lightning.

What to Do During a Thunderstorm

  • Go indoors immediately when you hear thunder
  • Remain inside until 30 minutes after the last thunder
  • Stay away from:
    • Windows
    • Doors
    • Electrical equipment
    • Plumbing (sinks, showers)

If you are outdoors and unable to reach shelter:

  • Avoid open areas, hilltops, and large field spaces
  • Stay away from tall objects (trees, light poles)
  • Do not lie flat on the ground
On Campus

During thunderstorms:

  • Move indoors to the nearest safe building
  • Avoid remaining on:
    • Athletic fields
    • Open courtyards
    • Construction areas

 Thunderstorms may produce lightning or escalate into more severe conditions, including tornadoes. While lightning requires immediate action based on visible conditions, tornado warnings are issued through Canada’s Alert Ready system.

Tornado Warnings: How You Will Be Notified

Tornado warnings in Canada are issued by Environment Canada and delivered through Alert Ready, Canada’s national public alerting system.

Alert Ready:

  • Sends immediate, mandatory alerts to mobile devices, television, and radio
  • Is geo-targeted to people within the affected area
  • Cannot be turned off and is designed for lifesafety emergencies

Alert Ready is the primary warning system for tornadoes. The University of Waterloo relies on Alert Ready to deliver tornado warnings.

When the University Will Communicate

The University does not duplicate tornado warnings issued through Alert Ready.

Instead, the University will provide additional communication only when campusspecific information or action is required, including:

  • Confirmed impacts on campus (e.g., damage, hazards, power outages)
  • Operational disruptions (e.g., class or exam cancellations, building closures)
  • Campusspecific safety instructions (e.g., where to shelter, areas to avoid)
  • Allclear or recovery updates

You may not receive a separate University message during a Tornado Warning. This is because the lifesafety warning has already been delivered through Alert Ready.

What to Do When You Receive a Tornado Warning

When you receive a Tornado Warning through Alert Ready:

  • Go indoors immediately
  • Move to the lowest level of a building
  • Stay in an interior space, away from windows and exterior walls
  • Avoid large open areas such as gymnasiums, atriums, or lecture halls
  • Remain in place until the threat has passed
Sheltering on Campus

If you are on campus, the safest spaces include:

  • Interior hallways
  • Lowerlevel rooms
  • Areas without windows

Avoid:

  • Glass atriums
  • Large open spaces
  • Areas near windows or exterior walls
After the Storm

If there are impacts on campus, the University may provide updates through:

  • Email or campus notifications
  • The University website
  • Other official communication channels

These updates will focus on:

  • Safety hazards
  • Building access
  • Operational changes
  • Allclear messaging
Stay Prepared

You can prepare by:

  • Familiarizing yourself with Alert Ready notifications
  • Knowing where to shelter in your building
  • Paying attention to weather conditions during severe weather events