The next test of the nuclear public alerting system will be November 23-24. 
The Province will test the Alert Ready system on November 25.

Durham Region regularly tests its public alerting system each fall and spring. The next test will occur November 23-24 during the day and will demonstrate what it would look and sound like during an emergency.

• November 23 – If you live within 10 kilometres of a nuclear generating station and have a landline phone, you will receive an automated phone call.  


• November 24 – If you are outdoors and within 3 kilometres of a nuclear generating station, you will hear sirens sound for one minute.   

The Province of Ontario will also be testing the Alert Ready system. They will issue a test message over television, radio, and compatible wireless devices:

• November 25 – If you have a compatible cell phone, you will receive an Alert Ready message from the Province. 

https://www.durham.ca/en/living-here/nuclear-preparedness.aspx