Thunder Bay is facing a double punch of wild weather this week as Environment Canada has issued two alerts for the city: a severe thunderstorm watch for tonight and the first heat warning of the season starting Tuesday. The mix of possible large hail, damaging winds, and then a stretch of sweltering humidity has officials urging people to stay alert and check on neighbours.
The thunderstorm watch warns that conditions are ripe for dangerous storms this evening and overnight. Wind gusts could whip up to 110 km/h, hail could be as big as golf balls, and heavy downpours could dump 50 to 75 millimetres of rain in a short time. At the Thunder Bay Airport late Monday afternoon, it was a humid and misty 16°C with an east wind at 15 km/h and falling pressure—a sign that the weather is changing fast.
Once the storm threat passes, the heat settles in and it will stick around for days. Environment Canada says temperatures will climb to between 29°C and 32°C from Tuesday through Friday, with some days possibly hitting 33°C. It will feel even hotter, with humidex values reaching 36 to 41. Overnight lows will barely dip to 16°C to 19°C, and on the hottest days may only fall to 18°C to 22°C, so there won’t be much relief after the sun goes down. For perspective, the normal high for this time of year is 23°C, with overnight lows around 10°C.
Tuesday’s UV index is forecast at 9, which is very high, meaning sunburns can happen fast especially when combined with the heat. The warmth follows a June that started cooler than usual—about half a degree below normal—but a shift in the weather pattern has opened the door for hotter, more humid air. Experts say a developing super El Niño could make this summer one of the warmest on record for the Thunder Bay area.
With the heat warning in effect for the first time this year, officials remind everyone to take it seriously. Heat stroke is a medical emergency—symptoms include red, hot skin, dizziness, nausea, and confusion. Check in regularly on older adults, young children, people with chronic health issues, and anyone who lives alone. If someone shows signs of heat stroke, call 911 right away. As the city braces for the storms tonight and then the heat wave that follows, staying connected and taking simple precautions can make all the difference.
