You won't need your sweater, but you might need an umbrella.
According to The Weather Network, daytime highs will remain 5 to 7 C above seasonal across most of the province for some late-August vibes.
Areas such as Ottawa, Cornwall and Huntsville could feel as high as 24 C on Tuesday thanks to an abundance of sunshine.
However, with the heat comes a looming threat of heavy rain, large hail and strong winds.
"Thunderstorms are expected across a good chunk of Ontario on Monday, though the area where storms are expected to be more frequent and widespread is going to be in northeastern sections," Matt Grinter, TWN meteorologist, said.
Anyone waiting for sweater weather to arrive will have to be patient as temperatures are expected to stay above seasonable through the weekend.