Thunder Bay Wakes to a Frosty Morning and a Glorious Forecast
Thunder Bay is starting this Wednesday, May 7th, the way it knows best—brisk and beautiful. At 6:00 AM EDT, the temperature sits just above freezing at 0.6°C, with the sky mainly clear. There’s barely a breeze, with north winds at just 2 km/h, and the humidity is at a high 92%, making it feel a little damper than it looks. Visibility is excellent at 32 km, and the barometric pressure is rising at 102.6 kPa, setting the stage for a dry and sunny shift.
A couple of sure signs of spring. Crews are out at Port Arthur Stadium working on the field getting set for the Border Cats season and second, the ticket office for the Thunder Bay Border Cats is open.
Today’s Forecast – From Mixed Skies to Full Sunshine
The morning will feature a mix of sun and cloud, but skies will clear this afternoon, treating Thunder Bay to a bright and crisp spring day. East winds will pick up to 20 km/h, easing off later in the morning. The daytime high will reach 12°C, a modest but comfortable rise from the frosty start. The UV index is 6, so don’t forget sunscreen, especially as the sun begins to dominate the skies.
Tonight, the skies stay clear, with temperatures cooling down to a low of 0°C. A jacket is still your best friend once the sun dips.
Thursday to Saturday – Big Bounce, Big Smiles
Thursday, May 8, brings uninterrupted sunshine, though it remains a bit cooler with a high of 10°C. Still, the UV index climbs to 7, so don’t let the temperature fool you—the sun means business. Overnight, it gets chilly again with a low of -2°C, so keep those extra blankets handy.
But then comes the spring jackpot: Friday, May 9, will bring sunny skies and a remarkable high of 24°C—yes, you read that right. That’s a 23-degree jump in just two days! The night remains clear and comfortable with a low of 8°C.
Saturday, May 10, sees temperatures moderate slightly with a sunny high of 15°C and a low of 3°C. It’s the kind of spring week that practically demands a patio lunch… and a few wardrobe changes.
What to Wear in Thunder Bay Today?
This morning, think hat, gloves, and a warm coat, especially if you’re heading out before sunrise. By the afternoon, a light jacket or sweater should do just fine. And with sunny days ahead, sunglasses and sunscreen should move to the top of your “don’t leave the house without it” list.
Historic Weather Fun Fact
On this date in Thunder Bay history, the warmest May 7th was a balmy 27.8°C in 1977, while the coldest plunged to -6.1°C in 1979. Today’s slow warm-up fits right in with Thunder Bay’s spring tradition—never boring, often brisk, and full of surprises.
Weather Trivia – Why It’s So Chilly in the Morning?
Thunder Bay’s location near Lake Superior contributes to some impressive overnight cooling. With clear skies and dry air, the ground loses heat quickly at night—leading to those sharply cold mornings, even in May. But once the sun rises, temperatures often leap back up, making this one of the most dramatic daily swings in Ontario.
