Heat and humidity are returning at an all-time high to Toronto after a chilly bout of spring-like weather over the weekend.

The extreme heat marks the first official week of summer, and temperatures could feel as hot as 40 C by Tuesday.

The UV index is also expected to reach 10 tomorrow, so it’s a good idea to double up on sun screen if you’re going to be outside.

According to the Weather Network, an usually strong ridge of high pressure is trapping some of the hottest temperatures and humidex values so far this year.

As the week progresses, temperatures will reach the low to mid-30s and humidex values will climb into the 40s.

The first official week of summer will be a hot one in Ontario ☀🔥 Daytime highs will climb to the low to mid-30s with humidex values into the 40s most of the week. https://t.co/Nx5fmg2Mvy

— The Weather Network (@weathernetwork) June 20, 2022

The GTA can breathe for now, as the extreme gust of heat isn’t set to arrive until tomorrow afternoon.

However, the hot weather is expected to remain as the Weather Network reports there will be “no relief in sight for the foreseeable future.”

On Wednesday, there is a risk of thunderstorm in Toronto as temperatures feel as hot as 38 C.

The heat wave is expected to extend into the weekend, where we’ll still see humidex values in the low to mid 30s.