A Cold Start, but Sunshine Sticks Around as Warmer Days Inch In
Brace for Brisk, But Hope for Heat—Thunder Bay’s Forecast Is Slowly Thawing
Thunder Bay, ON – Tuesday, April 8, 2025 – This morning in Thunder Bay is not exactly patio weather unless you’re into snow-covered lawn chairs and hot coffee that turns to iced lattes within minutes. As of 6:00 AM EDT, the thermometer reads a brisk -12.9°C under clear skies, with a west-southwest breeze at 10 km/h making it feel like -19°C. The wind chill dipped to -21°C earlier this morning—decidedly not flip-flop friendly. The air is dry but not desert-like, with humidity sitting at 68%. Barometric pressure is at 102.3 kPa and trending downward, hinting at a shift in weather coming midweek.
Today’s forecast holds onto the sunshine, with clear skies expected throughout the day. Winds will stay light, maxing out around 15 km/h. The high? A humble zero degrees—barely enough to make a snowbank sweat, but with the sun overhead and a UV index of 4 (moderate), it’s still a good idea to keep sunglasses or sunscreen handy, especially with reflective snow still on the ground.
Tonight continues clear and calm, but the mercury will drop once again to -11°C. Wind chill readings will dip to -13°C overnight, though it will feel slightly milder early in the evening at around -5°C. Not quite tropical, but manageable if you’re bundled up properly.
On Wednesday, April 9, the sunny streak keeps going. Winds stay gentle, and the daytime high creeps up to +1°C—progress! The morning wind chill, however, will again feel like a bitter -14°C, so expect another cold sunrise. Overnight skies remain partly cloudy with a low of -5°C.
Thursday brings a touch more variety, with a mix of sun and cloud and a more seasonable high of 6°C. Evening temperatures slip to -6°C. Friday continues the climb with highs reaching 8°C under partly sunny skies, and lows staying just below freezing at -3°C.
Saturday and Sunday really usher in the spring vibes with temperatures rising to 10°C and 12°C respectively. Nights will be milder too, with lows staying around zero or just above freezing. If you’ve been waiting for the “real” spring to arrive, the weekend may finally deliver.
What to Wear:
Start your day dressed for a winter morning—heavy coat, gloves, scarf, and hat. By midweek, you might trade the parka for a lighter jacket, especially during the afternoon sun. Layers are your best bet as we ride this temperature roller coaster. And don’t forget sunscreen—even snow-glare sunburns are real!
On This Day in Weather History:
Thunder Bay’s historical high for April 8 is a lovely 17.5°C, while the coldest on record is a biting -22.6°C. Today’s -13°C start puts us somewhere in between, though a little closer to parka than picnic.
Weather Trivia Time!
Did you know? Thunder Bay sees more sunshine annually than any other city in Ontario—over 2,100 hours on average! So while it may be frosty now, those clear skies are just flexing the city’s sunny reputation.
