Loud alerts will blare from phones, televisions, and other digital devices across Ontario this week as part of a national test of the Alert Ready system. The nationwide test of the alert system will take place on Nov. 19 with different times scheduled for all 13 provinces and territories. Here's everything you need to know about the Alert Ready test in Ontario this week. A nationwide test of the #AlertReady system will take place Wednesday over television, radio and compatible wireless devices. Here's everything you need to know to prepare 👇 pic.twitter.com/zDYp61ZFwx — Alert Ready (@AlertReady) November 17, 2025Ontario residents will hear that trademark jarring alert tone blasting from their devices at 12:55 p.m. on Wednesday, Nov. 19.