Thunder Bay Weather Update: Sunshine After a Deep Freeze, Snow on the Way Tonight

Thunder Bay Chills at –20°C, Mild but Messy Weekend Ahead

Clear, Cold Morning with Snow Lining Up for Tonight

Thunder Bay is waking up under a bright but bitterly cold sky this morning. At 7:00 a.m. EST at Thunder Bay Airport it was clear with a temperature of –19.5°C, feeling closer to –29 with the west wind at 17 km/h. Humidity is sitting near 67 percent, visibility is a crisp 24 kilometres, and the barometric pressure is at 100.9 kPa and rising as high pressure builds in behind yesterday’s winter storm. It looks pretty, but exposed skin will notice that wind chill very quickly on the way to school, work, or the bus stop.

Through the morning there’s a lingering forty percent chance of flurries, but skies are expected to clear as the day goes on. Winds will swing to the northwest at about 20 km/h with gusts up to 40 before easing off later this morning. The daytime high will manage only about –12°C, and with that lingering breeze it will still feel closer to –27 this morning and –16 this afternoon. It’s another day for the full winter kit: insulated jacket, toque that covers your ears, warm mitts, winter boots, and a scarf or neck tube to protect your face from the wind.

Tonight and Saturday: Snow Returns, Then Falling Temperatures

The quiet sunshine won’t last. Clouds will thicken again this evening, and a fresh round of snow is on the way. Snow is forecast to begin this evening with two to four centimetres expected overnight. Winds will pick up from the south at 30 km/h, gusting to 50 late this evening before easing again toward morning. As that milder air pushes in, the temperature will actually rise, reaching around –4°C by Saturday morning. Even with the warm-up, it will still feel around –19 this evening and about –8 overnight when you factor in the wind chill.

On Saturday the snow tapers off in the morning, leaving behind a mostly cloudy sky and about a forty percent chance of lingering flurries. As the low pressure system slides east, winds swing around to the west at 30 km/h early in the afternoon, dragging colder air back into the region. The daytime temperature will actually fall to around –12°C in the afternoon. It will feel close to –8 in the morning and near –23 by afternoon with that west wind. Saturday night stays unsettled, with cloudy periods, a continuing forty percent chance of flurries, and a low near –18°C. Driving conditions on regional highways and city streets may be slick at times, especially during and just after the snow tonight and again with falling temperatures and flurries on Saturday.

Looking Ahead: Brighter but Still Wintry Before a Mild Nudge

Sunday brings a welcome break in the pattern with a classic northwestern Ontario winter day: a mix of sun and cloud, a daytime high near –12°C, and a clear and very cold night dipping to around –24°C. Monday sees increasing cloud with a high around –4°C and the next wave of snow moving in Monday night with a sixty percent chance of snow and a low near –7°C. Through midweek, flurries and cloud remain in the picture, but temperatures look like they’ll hover closer to the single digits below zero than the deep freeze we’ve just been through.

What to Wear and How to Cope

For today and tonight, think practical, layered, and warm. Start with a thermal base layer, add a fleece or sweater, then a windproof winter coat. Insulated boots, thick socks, and mitts will keep fingers and toes much happier than thin gloves or runners on icy sidewalks. With tonight’s snow and gusty winds, give yourself extra time if you’re driving, and make sure your car has a scraper, brush, and a bit of emergency gear in case you get stuck in a snow pile or slow traffic.

Thunder Bay Weather Trivia

Thunder Bay’s winter personality is shaped by its location on the north shore of Lake Superior. Storm systems often ride up along the lake, which can occasionally add a little moisture and warmth, but once the Arctic air pushes in behind those systems, the city can swing quickly from wet and slushy to bright, dry, and bitterly cold. That’s exactly the pattern we’re seeing now: sunshine and deep cold today, followed by another fast-moving system tonight and a return to more typical December chill.

Last Word on the Weather: Thunder Bay starts at –20°C under clear skies, then snow arrives tonight with 2–4 cm and falling temperatures again Saturday. Get the full weekend weather outlook.