July 25, 2025: Toronto’s Detailed Weather Forecast – Heat Warning in Effect

Toronto – Weather – Toronto is in the grip of a dangerous summer heat wave, with high humidity and temperatures creating intense and potentially hazardous conditions. Environment Canada continues to issue a Heat Warning for the City of Toronto, as the humidex soars near 40. Vulnerable individuals — including seniors, those living alone, young children, and outdoor workers — are strongly encouraged to take immediate precautions.

Today’s Weather Overview

Current Conditions (as of 7:00 AM EDT at Pearson International Airport)

• Temperature: 23.2°C

• Wind: West-northwest at 13 km/h

• Humidity: 87%

• Dew Point: 20.9°C

• Humidex: 32

• Pressure: 101.5 kPa (rising)

• Visibility: 19 km

• Sky Conditions: Mostly cloudy, with muggy air and minimal morning relief

Today, skies will transition from cloudy with a 40% chance of early showers to a mix of sun and cloud by the afternoon. The temperature will peak near 30°C, but with the humidex reaching 39, it will feel significantly hotter. The UV index is 8 – very high, so take extra precautions during peak daylight hours.

Tonight, conditions will remain partly cloudy and warm, with overnight lows only falling to 21°C, offering little overnight relief from the heat.

Forecast Conditions

Saturday, July 26:
The city will see mainly cloudy skies with a high of 29°C, and the humidex again climbing to 37. While slightly cooler than today, it will still feel oppressive, especially with cloud cover trapping heat. The UV index stays very high at 8.

Saturday Night:
Clouds persist with a 40% chance of showers, and a warm low of 22°C — some potential relief from rain, but continued humidity overnight.

Sunday, July 27:
Expect a mix of sun and cloud with a 40% chance of showers again. High of 30°C, and humidity will remain a factor.

Sunday Night:
Skies are expected to clear, and the low will dip to 21°C.

Monday, July 28:
A sunny, very hot day is forecast, with temperatures soaring to 32°C.

Monday Night:
Clouds return with a 40% chance of overnight showers and a warm low of 22°C.

Wardrobe and Safety Recommendations

• Clothing: Wear light-coloured, loose-fitting clothing and a wide-brimmed hat. Lightweight fabrics such as cotton or moisture-wicking materials will help regulate body temperature.

• Hydration: Drink water often, even before feeling thirsty. Avoid alcohol and caffeine, which can accelerate dehydration.

• Sun Protection: Use sunscreen (SPF 30 or higher), and reapply frequently. Seek shade during peak sun hours (11 a.m. to 3 p.m.).

• Environment: Stay indoors or in air-conditioned environments as much as possible. Visit community cooling centres if needed.

• Health Monitoring: Watch for signs of heat exhaustion: headache, nausea, dizziness, fatigue, and dark urine. Take action immediately if these symptoms appear.

• Never leave children or pets in vehicles, even for short periods — interior temperatures can become fatal in minutes.

Weather Trivia

Did You Know?
Toronto’s urban landscape creates a phenomenon known as the “urban heat island effect,” where dense concrete, asphalt, and buildings absorb and retain heat. This can make nighttime temperatures up to 5°C warmer than surrounding rural areas — one reason why city nights during heatwaves stay uncomfortably warm.