An emergency public alert test will be broadcast on television, radio and sent to mobile devices on Wednesday.
Most people across the country are expected to get the interruption as the Canadian Radio-television and Telecommunications Commission (CRTC) says all provinces and territories, except Nunavut, will get the alerts, but people will not be required to take action.
The exact time of the test will vary depending on the province or territory.
The agency says testing the national public alerting system is aimed at checking performance and reliability "to ensure it operates as intended in the event of a life-threatening situation."
For a wireless device to receive a test alert, the CRTC says it must be connected to an LTE wireless or a newer wireless network, it must be wireless public alerting compatible and equipped with a recent Canadian version of its operating software.
If a mobile device meets these conditions and does not receive the test, the CRTC encourages Canadians to contact their service provider.
— With files from The Canadian Press