Thunder Bay – WEATHER – Thunder Bay is starting the week with a hard shot of cold, then flipping quickly back into active winter weather. Monday stays bright but frigid, with frostbite risk in the morning. By tonight, cloud thickens and snow begins before daybreak, setting up a steady snow day Tuesday with about 10 cm expected.
Today’s Weather Overview
Current Conditions
As of 6:00 AM EST at Thunder Bay Airport, conditions are partly cloudy and sharply cold:
The temperature is -22.3°C, and a NNW wind at 15 km/h is driving the wind chill to -32. Humidity is 66%, with a dew point of -26.9°C. Visibility is 24 km. Barometric pressure is 104.2 kPa and rising, which often supports calmer skies—but not warmer air.
Today
It will be sunny, becoming a mix of sun and cloud this afternoon. Winds remain light (up to 15 km/h), but the cold stays intense.
The daytime high reaches -15°C. Wind chill values are expected near -30 this morning and around -19 this afternoon. The UV index is 2 (low).
Extended Thunder Bay Weather Forecast
Expected Conditions
Tonight (Mon night):
Skies turn mainly cloudy, with a 30% chance of snow, and snow begins before morning. About 2 cm is expected overnight. Winds become southeast 20 km/h toward morning. The low is -17°C, but temperatures rise toward -10°C by daybreak, with wind chill near -22.
Tuesday, February 24:
Thunder Bay moves fully back into the snow zone with snow throughout the day. Total snowfall is expected to be about 10 cm. Winds start south 20 km/h, turning west 20 km/h near noon. The high is -4°C, with wind chill near -19 in the morning and -10 in the afternoon. The UV index is 1 (low).
Tuesday night:
Cloudy periods with a 60% chance of flurries, low -12°C.
Wednesday, February 25:
A mix of sun and cloud with a 40% chance of flurries, high -8°C.
Wednesday night: Clear, low -18°C.
Wardrobe Recommendations
Monday morning is “full winter armour” weather: a warm base layer, insulated mid-layer, and a wind-resistant parka. Use mittens, a warm hat, and a neck gaiter/balaclava if you’ll be outside for more than a few minutes.
For Tuesday’s snow: switch to water-resistant outerwear and boots with traction. Visibility and road spray will be an issue—top up winter windshield washer fluid and keep the brush/scraper handy.
Weather Trivia
That “low of -17°C, then rising to -10°C by morning” tonight is a classic sign of warmer air pushing in ahead of a snow system. Temperatures can actually climb overnight while the sky turns snowier—Thunder Bay winter loves a plot twist.
Summary
Thunder Bay weather forecast for Monday, February 23, 2026: sunny but bitterly cold with wind chill near -30 this morning and a high of -15°C. Snow develops overnight, with about 10 cm expected Tuesday and continued flurries into midweek.
