Breezy Lake Superior Keeps Thunder Bay Comfortable Amid Regional Heat Warnings
THUNDER BAY – WEATHER REPORT – While much of Northwestern Ontario is sweating under a spring heatwave, Thunder Bay is proving that sometimes, it pays to be beside the big lake. Thanks to the cooling influence of Lake Superior, the city is enjoying a much more comfortable stretch of weather—making it a refreshing pocket of calm in an otherwise steamy region.
Sunny, Cool, and Classic Thunder Bay: Forecast Through Thursday
At 7:00 AM EDT this morning, it’s a brisk 4.6°C at Thunder Bay Airport under partly cloudy skies. Humidity is sitting at 88%, with a dew point of 2.8°C, giving the air a bit of a damp early-spring feel. Winds are barely making a ripple at 3 km/h from the north-northwest, and the barometric pressure is a steady 101.6 kPa and on the rise—signaling settled and sunny conditions.
Today will be sunny with temperatures climbing to a pleasant 23°C—perfect patio weather without the sweat factor. The UV index, however, is soaring to 8, which is considered very high, so make sure to layer on the sunscreen if you’re venturing out, even if it still feels cool in the shade.
Tonight will be clear and cool with temperatures dropping to 5°C—ideal for cracking the windows and enjoying some natural air conditioning.
Tuesday brings another sun-soaked day with a high of 24°C. The UV index remains at 8, so once again, sun protection is a must. The night will be clear and comfortable with a low of 8°C.
By Wednesday, clouds start to mix in, with a 30 percent chance of showers in the forecast. The high will reach 23°C, followed by a cloudy night with a similar 30 percent chance of showers and a low of 7°C.
Thursday brings more clouds and another 30 percent chance of showers, with the high easing back to 18°C—still comfortable, but noticeably cooler than earlier in the week. Showers will continue Thursday night with a low of 9°C.
What to Wear for Lake Superior’s Breezy Spring
Today is one of those days where the thermometer might read “warm,” but the breeze off Lake Superior tells a different story—especially in the morning and near the water. Light layers are your best friend, with a jacket for the morning that can be shed by afternoon. And don’t forget the sunscreen—the sun might feel gentle, but it’s still packing a punch.
Historical Weather for May 12
Thunder Bay’s record high for this day is 29.1°C, while the record low sits at a chilly -3.9°C. Today’s high of 23°C lands right in the comfortable sweet spot, showing off Thunder Bay’s signature springtime mood swings.
Local Weather Trivia
Did you know? Lake Superior is so massive it can cool—or heat—the surrounding area for weeks at a time. In fact, on days when much of Northwestern Ontario is baking, Thunder Bay often enjoys “lake-cooled” air that can be up to 10 degrees cooler than inland areas. Just another perk of living by the greatest of the Great Lakes.
