Environment Canada announced a yellow heat warning for the Greater Toronto Area, covering the period from Monday, July 13, 2026, through Thursday, July 16, 2026. The agency highlighted that temperatures are expected to climb to a peak of 37 °C on Tuesday, with humidex values approaching 45 °C, signalling a significant heat wave across the region.
The yellow heat warning, the first level of heat advisories issued by the agency, is triggered when humidex readings are forecast to reach the mid‑40s Celsius. In this case, the projected humidex of 45 °C reflects a combination of high temperature and humidity that can increase the perceived heat and pose health concerns for residents.
During the warning period, the forecast calls for consistently high temperatures throughout the Greater Toronto Area. While the highest temperature is anticipated on Tuesday, the overall pattern suggests a sustained period of warmth, with humidex values remaining near the advisory threshold for several days. The warning remains in effect until the end of Thursday, July 16, unless conditions change.
Environment Canada’s issuance of the warning serves to alert municipalities, emergency services, and the public to the expected conditions. The agency monitors temperature and humidity trends closely, and the yellow warning indicates that the public should be aware of the increased heat risk, especially for vulnerable groups such as the elderly and those engaged in outdoor activities.
The agency will continue to provide updates as the heat wave progresses, and the warning may be adjusted if temperatures rise further or if the humidex exceeds the current forecast. Residents are encouraged to stay informed through official channels as the situation develops.