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What to do during a thunderstorm

Calgary is prone to thunderstorms, and all thunderstorms have the potential to be dangerous. Every thunderstorm produces lightning, which injures more than 150 people in Canada every year.

What causes thunderstorms?

Thunderstorms are caused by strong rising air currents and are most likely to develop when weather is hot, humid, and hazy. Cooler air coming from the higher elevation of the Rocky Mountains hits the warmer air rising from the ground in the Foothills, which creates an unstable air mass. Thunderstorms are most common in June, July and August, but can occur any month of the year.

What are the dangers?

Strong winds, hail and tornados are dangers associated with some thunderstorms. Damage from these winds can equal the damage of most tornadoes. Heavy rain from thunderstorms can also lead to flash flooding.

What should I do before a thunderstorm hits?

Grab your 72-hour kit and go to a safe place! This should be a place without windows or glass doors. If a sturdy building is not nearby, get into a hard-topped metal vehicle and close the windows. Stay inside until 30 minutes after the last rumble of thunder.

How do I know a thunderstorm is coming?

View public weather alerts for Alberta and subscribe to Alberta Emergency Alerts to stay informed.

A “severe weather watch” from Environment Canada indicates that conditions favour the occurrence of a certain type of hazardous weather. Monitor weather conditions through a local media station or website, and take appropriate precautions.

A “severe weather warning” issued by Environment Canada indicates that a hazardous event is imminent in about 30-60 minutes. You should seek shelter indoors and continue to monitor weather conditions.