Toronto Heats Up: 30°C and Humidex 35 with Showers and Thunder Possible Tonight

TORONTO – Toronto is waking up to a warm and sunny morning with a fast climb in temperature and humidity ahead. Expect a hot and hazy afternoon with a humidex reaching 35, making today feel more like mid-July than early June. Showers and a risk of thunderstorms will move in this evening, offering potential relief from the heat but also raising storm safety concerns.

Today’s Weather Overview

Current Conditions

As of 7:00 AM EDT, conditions at Toronto Pearson International Airport are mainly sunny with a temperature of 18.1°C. The humidity is at 61%, and the dew point is 10.5°C, signaling a comfortably warm start. Winds are light from the south-southeast at 8 km/h, and visibility is 19 kilometres.

Barometric pressure is at 101.6 kPa but falling, signaling an approaching change in weather — confirmed by this evening’s forecast for showers and potential thunderstorms.

Today will remain sunny and hazy, with winds becoming southwest at 20 km/h, gusting to 40 km/h by late morning. The afternoon high will soar to 30°C, with a humidex of 35, and the UV index is 9 – very high. Sun protection is absolutely essential.

Tomorrow’s Forecast

Expected Conditions

Thursday, June 5: Expect a cloudy start with a 70% chance of showers, decreasing to a 30% chance by midday, and clearing late in the afternoon. There is also a risk of a thunderstorm in the morning and early afternoon. Hazy skies may return late in the day. Winds will shift north at 20 km/h, becoming light by midday. High of 23°C, with a humidex of 26 and UV index of 7 (high).

Thursday Night: Skies will clear, and it will be a cooler night with a low of 14°C.

Friday, June 6: A mix of sun and cloud continues, with a 30% chance of showers and a high of 23°C.

Friday Night: Cloud cover increases with a low of 14°C.

Wardrobe Recommendations

• Today: Lightweight, breathable clothing is key. Sunglasses, a hat, and high-SPF sunscreen are essential with the UV index at 9. Keep water close at hand and avoid strenuous activity during the afternoon heat.

• Thursday: Dress for variability — rain gear in the morning, then lighter clothes as it clears. Smoke and haze could return in the afternoon.

• Friday: Comfortable summer attire, with a light jacket or umbrella for potential showers.

Weather Trivia

Did you know?
Toronto has one of the most variable early summer climates in Canada, with temperatures swinging from single digits to 30°C+ within a week. The city’s proximity to Lake Ontario also influences wind and storm development, sometimes intensifying summer thunderstorm activity — especially on days like today when heat and moisture collide.