Toronto is expected to see some relief from a prolonged heat wave as a cooler air mass is forecast to arrive Tuesday night. Environment Canada issued a multi-day heat warning on Saturday, indicating that temperatures could feel as high as 42 degrees Celsius due to humidity. While the cooler air is anticipated, the Greater Toronto Area (GTA) and eastern Ontario may still experience hot and humid conditions into Wednesday.

On Tuesday, temperatures are predicted to reach a high of 32 degrees Celsius, feeling more like 40 with humidity. The day will start with a mix of sun and clouds, and there is a 30 percent chance of showers developing late in the afternoon. The risk of thunderstorms is also present. As the evening approaches, the chance of rain increases to 40 percent, with a low temperature of 22 degrees Celsius.

Wednesday's forecast includes a continued 40 percent chance of showers and possible thunderstorms, particularly in the late morning and afternoon. The high temperature is expected to be 30 degrees Celsius, but it will feel like 37 with the humidex. The night will bring clearer skies and a low of 18 degrees Celsius.

Looking ahead, Thursday's temperatures are expected to drop slightly to a high of 29 degrees Celsius under sunny conditions, with a clear night following and a low of 19 degrees Celsius. Friday will see more sunshine, with a high of 30 degrees Celsius and a low of 21 degrees Celsius.

Saturday is forecasted to be sunny with a high of 32 degrees Celsius, but clouds may roll in at night, bringing a 40 percent chance of showers and a low of 20 degrees Celsius. Sunday is expected to be partly overcast, with a high of 23 degrees Celsius and a continued chance of rain.

In light of the heat, Environment Canada has provided safety tips to help residents avoid heat-related health risks. The agency emphasizes the importance of checking on older adults and those living alone multiple times a day. Symptoms of heat stroke and heat exhaustion, such as headache, nausea, dizziness, and intense fatigue, should be monitored closely. To stay safe, residents are advised to drink water regularly, limit sun exposure, and schedule outdoor activities during cooler parts of the day. Additionally, it is crucial never to leave children or pets inside parked vehicles.