A heat warning remains in effect for Toronto today but some relief is expected to arrive this weekend. Environment Canada is calling for a high of 30 C today, feeling closer to 39 with the humidity. Saturday will see a high of 29 C, feeling like 37 when factoring in the humidity.

With extreme heat warnings in effect across major U.S. cities, officials urge residents to prioritize safety and hydration during this dangerous heat wave.

From Texas to New England, millions of Americans are facing dangerously hot temperatures that have led the National Weather Service to issue heat advisories and extreme heat warnings this week.

On Thursday, we warm to 90 again, and on Friday we'll be pushing 100, certainly reaching (and exceeding) when accounting for the humidity and the feels-like temps. Dewpoint temps will be going back into the mid-70s, so get ready to sweat when heading outside.

Much of the U.S. is under extreme heat warnings or advisories while New York, Philadelphia and Washington could feel like 100 degrees or more.

A heat warning has been issued for part of southern Ontario. Environment Canada said a “heat event” is expected to begin Thursday. Toronto, Mississauga, Brampton, Hamilton and Niagara Region are among the areas covered by the warning.

Extreme heat warning issued for parts of Delaware, New Jersey, and Pennsylvania, with heat index up to 106 degrees.

The heat dome won't dissipate soon. Dangerous heat is expected across parts of the Central and Southeast. through July, the weather service says. High temperatures will reach 100 degrees from Texas to western Tennessee almost every day for a week or two, AccuWeather said.