Heat Warning Issued for Toronto, Temperatures Could Hit 37°C

TORONTO, July 13, 2026 – To quote my grade 4 French teacher, “Il fait chaud aujourd’hui.” And that is expected to be the French phrase of the day for the next couple of days as Environment and Climate Change Cana (ECCC) has issued another Heat Warning for Toronto as a new stretch of dangerously hot and humid weather settles over southern Ontario.

Temperatures are expected to range between 30°C and 37°C, with Tuesday forecast to be the hottest day of the heat event. Combined with the humidity, it could feel as hot as 45°C, increasing the risk of heat-related illnesses across the city.

This Heat Warning is classified as Yellow , meaning moderate, and is expected to remain in effect until Wednesday evening or Thursday evening, depending on how quickly cooler air moves into the region.

Monday will be super hot and Tuesday is expected to bring sizzling hot conditions

ECCC says Tuesday will bring the highest temperatures, with some areas around the Greater Golden Horseshoe expected to reach 37°C. Overnight lows of 20°C to 24°C will offer little relief, making it difficult for homes without air conditioning to cool down.

The prolonged heat and humidity could also cause air quality to deteriorate, with the Air Quality Health Index (AQHI) approaching the high-risk category.

Who is most at risk?

While extreme heat can affect anyone, older adults, infants and young children, people with chronic medical conditions, outdoor workers and those without access to air conditioning face the greatest risk of heat-related illness.

Environment and Climate Change Canada is urging residents to check in regularly on older relatives, neighbours and friends, especially those living alone.

Know the signs of heat illness

Early symptoms of heat exhaustion may include:

Headache
Dizziness
Nausea
Excessive thirst
Dark-coloured urine
Extreme fatigue

Anyone experiencing these symptoms should stop their activity, move to a cool place and drink water.

Heat stroke is a medical emergency. Symptoms can include hot, flushed skin, confusion, dizziness, nausea or loss of consciousness. Call 911 immediately if someone is showing signs of heat stroke while taking steps to cool them by moving them into an air-conditioned space or shaded area and applying cool water or ice packs.

Tips to stay safe

Environment and Climate Change Canada recommends:

Drink water often, even before you feel thirsty.
Limit strenuous outdoor activities during the hottest part of the day.
Wear lightweight, loose-fitting, light-coloured clothing and a wide-brimmed hat.
Close blinds or curtains during the day and use air conditioning or fans whenever possible.
If your home becomes too hot, visit a cooling centre, community centre, library or another air-conditioned public space.
Never leave children, older adults or pets unattended in a parked vehicle.
If wildfire smoke affects your area, prioritize staying cool while following local air quality advisories.

Forecasters expect temperatures to ease later this week, although the timing will depend on the arrival of a cooler air mass moving into southern Ontario.

Toronto residents are encouraged to monitor the latest forecasts and weather alerts, as the Heat Warning could be extended or updated if conditions change.