OTTAWA, June 18 -- Extreme heat wave warnings are in effect for central and eastern Canada with temperatures feeling as warm as low 40s on Tuesday, CTV News reported.

According to the report, Ontario, Quebec, New Brunswick and Nova Scotia are under extreme heat warnings with humidex values up to 45 through most of the week.

In northwestern Ontario, a risk of tornado is issued for Tuesday afternoon. Thunderstorms are forecast for Tuesday morning, and the afternoon ones will be the most intense. Wind gusts are forecast up to 90 km/h with large hail and heavy rainfall, CTV News reported.

According to Environment Canada, daytime highs through much of the week in Toronto, the largest city in Canada, are expected to be 30 to 35 degrees Celsius with humidex values of 40 to 45.

There will be little relief through the overnight as lows are expected to be 20 to 23 degrees Celsius with humidex values of 26 to 30, the weather agency said.

Hot and humid air can also bring deteriorating air quality and can result in the Air Quality Health Index approaching the high risk category, Environment Canada added.

  - Xinhua