Summer officially begins this week, and southern Ontario is set to feel every bit of it as a multi-day heat event rolls in starting Sunday, according to Environment and Climate Change Canada.
The heat warning, in effect from Sunday through Wednesday, June 25, is expected to bring daytime highs into the mid-30s across the region, including Toronto, Brampton, Mississauga, Oakville, Hamilton, Niagara, and Durham.
Temperatures will start climbing on Friday, with a high near 25°C and partly sunny skies along with a chance of thunderstorms. Saturday will heat up further with highs near 29°C under mostly sunny skies, though evening showers are possible.
The real swelter sets in Sunday, with forecasted highs around 33°C and overnight lows of 23°C, offering little nighttime relief. The extreme heat continues into early next week, with highs of 34°C expected on both Monday and Tuesday.
Environment Canada is urging residents to stay hydrated, avoid outdoor exertion during peak heat hours, and watch for signs of heat-related illness such as dizziness, nausea, or rapid heartbeat.
Cooling centres will be open in most communities, and those without air conditioning are encouraged to seek relief at malls, libraries, or splash pads.
With several hot days ahead, public health officials remind everyone to check on vulnerable family members and neighbors, especially seniors, children, and people with chronic health conditions.