It says "a very warm and humid airmass" will settle over eastern Quebec and the Maritime provinces this weekend, and will last into next week. Daytime temperatures will again be near 30 degrees, with humidex values in the mid 30s.
There won't be much relief overnight, either.
Environment Canada has issued a heat warning for the City of Toronto forecasting that "extreme heat event will continue through Thursday", as humidex values are expected to reach 43ºC.More news: Start planning now for longest lunar eclipse of the century
A low of 24 C is in the forecast for the early morning hours on Sunday but the temperature will shoot back up to 35 C just in time for Canada Day celebrations.
"Extended periods of heat and humidity like we've seen over the weekend and are expecting over the next few days can be especially challenging for seniors, young children and those with medical conditions that put them at greater risk", said Randy Walker, public health inspector with MLHU.
In response to the extended heat warning, the city has opened a number of cooling centres around Toronto.More news: Trump plans to announce Supreme Court pick July 9
The extreme heat warning has also caused the Toronto Blue Jays to close the roof at Rogers Centre for Saturday's game against the Detroit Tigers as a precaution.
Environment Canada says the high heat and humidity could return on Wednesday. Slowdowns are often required as a safety precaution when the temperature execeeds 30 C. "Given the high temperatures - we had some issues already - I am anticipating that we will likely have a slow order issued across the system".More news: EU Leaders Reach 'Breakthrough' Agreement On Dealing With Migrants
- United States congressional delegation hopes Putin-Trump summit will be successful - senator
- Sanchez Reveals His Pick For World Cup Golden Boot
- Jesse Lingard full of praise for Gareth Southgate leading England 'revolution'
- Archbishop gets 12 months for concealing child abuse
- Mexico leftist vows no tolerance on corruption after historic win
- LeBron James: Basketball star agrees to join Los Angeles Lakers
- Scott Pruitt becomes latest Trump official to be harassed at a restaurant
- 'Dead' South African woman found alive inside morgue fridge
- Prince Harry Refused to Hold Meghan Markle's Hand
- Trump Says He Has Interviewed 4 Candidates For High Court