Thunder Bay – WEATHER – Thunder Bay is starting Saturday under mostly cloudy skies with rising pressure—a sign of stabilizing air—but the calm won’t last all day. A 40% chance of flurries hangs on through late morning/early afternoon before light snow develops later today and continues tonight.

Thunder Bay Roads crews have been out clearing snow. Road conditions will be slippery in places. Drive defensively.

By Sunday, northerly winds pick up and temperatures trend colder, ending with a clear, bitterly cold Sunday night.

Today’s Weather Overview

Current Conditions (Thunder Bay Airport, 8:00 AM EST)

• Temperature: -11.9°C (feels like -17 with wind chill)

• Condition: Mostly Cloudy

• Wind: WNW 9 km/h

• Humidity: 77% (Dew point: -15.1°C)

• Pressure: 102.0 kPa, rising

• Visibility: 32 km

What it feels like outside: cold, fairly clear visibility, and a dry-ish bite to the air—despite the cloud cover.

Tomorrow’s Forecast

Expected Conditions (Next Three Days)

Saturday (Today, Feb 21)

• Cloudy with a 40% chance of flurries this morning and early afternoon

• Light snow begins this afternoon

• Wind: Becoming northwest 20 km/h

• High: -5°C | Wind chill: near -16

• UV index: 1 (Low)

Tonight

• Periods of light snow, local amount ~2 cm

• Wind: Northwest 20 km/h

• Low: -9°C | Wind chill: near -17

Sunday (Feb 22)

• Cloudy with a 40% chance of flurries

• Wind: North 20 km/h gusting to 40

• Temperature falling to -12°C in the afternoon (a notable late-day drop)

• Wind chill: near -20

Sunday Night

• Clear and sharply colder

• Low: -23°C

Monday (Feb 23)

• Sunny

• High: -11°C

• Monday Night: Cloudy with 40% chance of flurries, low -17°C

Early week heads-up: Flurry chances return Tuesday, and daytime highs gradually moderate closer to seasonal levels midweek.

Wardrobe Recommendations

• Today: Winter coat + insulated boots. Add a windproof outer layer—NW 20 km/h will make -5°C feel colder.

• Tonight: If you’re out driving, plan for light snow accumulation and reduced traction. Warm gloves and a hat are a must.

• Sunday: Dress for gusty north winds (scarf/neck gaiter helps a lot).

• Sunday night: This is deep-winter cold (-23°C)—upgrade to heavier mitts, thicker socks, and cover exposed skin.

Weather Trivia

Thunder Bay’s weather often flips quickly because of Lake Superior’s influence. Even when pressure rises and skies try to clear, a wind shift to the north can drag in colder air fast—setting up that classic northwest Ontario pattern: cloud → flurries → clearing → big overnight drop.

Summary

Thunder Bay weather forecast for Saturday, Feb 21, 2026: mostly cloudy this morning with a 40% flurry risk, light snow developing this afternoon and tonight (about 2 cm), then gusty north winds Sunday and a clear, frigid -23°C Sunday night.