Ontario hosts Canada's newest hot spot as intense heat continues

Ontario will see its second heat event of the summer as temperatures and humidex values will take a considerable jump this week.

Temperatures will climb well into the 30s during the peak of the event this week, with humidex values easily reaching into the 40s.

DON'T MISS: Why extreme heat is one of the world's deadliest weather disasters

Even a relatively healthy individual can succumb to heat-related illnesses without proper precautions.

What could compound the heat issues will be the wildfire smoke that has reached parts of the province from Quebec, lowering air quality into this week.

Second heat event of the summer arrives

On Sunday, temperatures felt like the low 40s across northwestern Ontario as the heat and humidity continued to ramp up. Over twenty weather stations across the province recorded daytime temperatures above the 30-degree mark, and even hotter weather is still on the way!

In fact, one northwestern Ontario town now holds Canada's record for highest daytime temperature so far in 2026. Sioux Lookout, located north of Dryden, reached 38°C on Sunday!

The trophy may go to Sioux Lookout, but the temperatures felt in other communities throughout the region on Sunday were also noteworthy:

Sunday night will be shockingly warm in northwestern Ontario, with an overnight low of 25°C or 26°C forecast for Dryden, Kenora, and Fort Frances. Thunder Bay has a Monday overnight low temperature forecast of 25°C, extremely warm for the city.

Temperatures will continue to warm up on Monday, with Thunder Bay forecast to see a high of 38°C, feeling like 44 with the humidex. This comes only a couple degrees shy of the city's all-time hottest temperature: 40.3°C, which was set on Aug. 7, 1983.

These temperatures will be the warmest so far in 2026 across northern Ontario, with many communities forecast to exceed 35°C over the coming days.

On Monday, southern Ontario feels like the mid-30s once again, but now all of northern Ontario is feeling like the low 40s, with high moisture content in the atmosphere.

On Tuesday, the humidex values will rise even more.

A cold front is forecast to move into southern Ontario late Tuesday, bringing Wednesday's temperatures back down toward the 30-degree mark with humidex values staying in the low-to-mid 30s.

Extreme heat claims more lives around the world than any other type of severe weather.

Everyone is susceptible to heat-related illnesses without taking proper precautions, such as frequent breaks, adequate hydration, and air conditioning.

The compounding stress of hot days followed by muggy nights can be especially hard on vulnerable populations like the elderly, those with chronic health conditions, and folks who live without access to air conditioning. Keep in mind that certain medications can lower your body's heat tolerance.