Severe Thunderstorm

Thunderstorm messages

Stay aware of weather watches and warnings and know the difference between a watch and a warning.

  • Severe thunderstorm watch: When conditions are favourable for the development of severe thunderstorms with one or more weather conditions
  • Severe thunderstorm warning: When there is evidence based on radar, satellite pictures, or from a reliable spotter that one or more weather conditions is imminent or occurring

Weather conditions

  • Wind gusts of 90 kilometres per hour or greater, which could cause structural wind damage
  • Hail of two centimetres or larger in diameter
  • Heavy rainfall, as per rainfall criteria, excluding those for winter and during thaw

Before a severe thunderstorm

  • Keep your 72 hour kit in a place that's easily accessible even if the power goes out
  • Secure loose objects such as garbage cans that can injure people and damage property if they become airborne

During a severe thunderstorm

  • Seek shelter indoors
  • Stay away from windows, glass doors and skylights
  • Listen to weather warnings and information from local authorities. Use a battery powered or crank radio if your power is out.
  • Don't go outside to cover plants, garden furniture or to collect laundry once severe weather begins
  • Avoid parts of the building that could have something fall on it, such as overhanging branches
  • Stay indoors until at least 30 minutes have passed since the last rumble of thunder, even if you don't see lightning
  • Be aware that severe thunderstorms can have multiple hazards including lightning, damaging winds, hail, heavy rain, and rarely, tornadoes

If you're outside, move indoors immediately

  • If shelter isn't available, a hard top vehicle will provide the next best shelter, but don't touch any metal surfaces
  • A tree isn't a safe shelter as it may be struck by lightning or you may be injured by falling branches
  • Avoid water and wet surfaces since water conducts electricity
Page Feedback Did you find what you were looking for today?