Severe Thunderstorm Warning for Ontario

This alert expired on June 13, 2018 at 10:52:11 PM +0000
Environment Canada
Alert area: City of Toronto; Uxbridge - Beaverton - Northern Durham Region; Newmarket - Georgina - Northern York Region; Pickering - Oshawa - Southern Durham Region; Vaughan - Richmond Hill - Markham; City of Hamilton; Mississauga - Brampton; Halton Hills - Milton; Burlington - Oakville; St. Catharines - Grimsby - Northern Niagara Region

Posted June 13, 2018 at 8:21:11 PM +0000

At 4:20 p.m. EDT, Environment Canada meteorologists are tracking a cluster of severe thunderstorms capable of producing very strong wind gusts, up to nickel size hail and heavy rain.

This cluster of severe thunderstorms is located from East Gwillimbury to Bowmanville to Dundas to Acton, moving east at 75 km/h.

Communities in the path include: Milton, Burlington, Brampton, Oakville, Mississauga, Vaughan, Newmarket, Richmond Hill, Toronto, Markham and Pickering.


Large hail can damage property and cause injury. Strong wind gusts can toss loose objects, damage weak buildings, break branches off trees and overturn large vehicles.

Severe thunderstorm warnings are issued when imminent or occurring thunderstorms are likely to produce or are producing one or more of the following: large hail, damaging winds, torrential rainfall.

Recommended actions

Take cover immediately, if threatening weather approaches. Lightning kills and injures Canadians every year. Remember, when thunder roars, go indoors!

The Office of the Fire Marshal and Emergency Management recommends that you take cover immediately if threatening weather approaches.

Tips from

Excerpted from
  • Before a severe thunderstorm, unplug radios and televisions – listen for weather updates on your battery-powered radio.

  • Follow instructions for what to do before a severe storm


  • During thunderstorms, you should also stay away from items that conduct electricity, such as telephones, appliances, sinks, bathtubs, radiators and metal pipes.

  • Do not go out to rescue the laundry on the clothesline because it may conduct electricity.

  • If you are outdoors when a thunderstorm hits, take shelter immediately, preferably in a building but, failing this, in a depressed area such as a ditch, culvert or cave. Never go under a tree.

  • Follow instructions for what to do during a severe storm

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