Thunder Bay – WEATHER DESK – Thunder Bay is waking up to a steady, mid-winter cold with mostly cloudy skies over the city and airport. The daytime stays fairly calm (just gray and chilly), but the weather turns more active late tonight as snow arrives near midnight, with a risk of freezing drizzle before morning. Tuesday then brings a brief morning wrap-up to the snow, followed by flurries and a strong west wind that will make it feel sharply colder by afternoon.

Today’s Weather Overview

Current Conditions (Thunder Bay Airport — 6:00 AM EST)

As of 6:00 AM EST, Thunder Bay Airport reported mostly cloudy skies and -15.9°C with 82% humidity. The dew point is -18.3°C, and visibility is 24 km. Winds are WSW 9 km/h, creating a wind chill of -22. Barometric pressure is 102.5 kPa and rising, a sign the air mass is stable for now—even with snow on the way later.

Today (Monday, Dec. 22)

Expect cloudy/overcast skies with light winds (up to 15 km/h). The high reaches -4°C, and wind chills ease from about -17 this morning to around -6 this afternoon—noticeably more comfortable than the early start, but still winter-cold.

Tomorrow’s Forecast

Expected Conditions (Next 3 Days)

Tonight (Monday Night)

Cloudy skies continue, with snow beginning near midnight. There’s a risk of freezing drizzle before morning, and snowfall totals are expected to be 2 to 4 cm. Wind remains light (up to 15 km/h). Low: -7°C, with wind chill near -15 overnight.

Tuesday, Dec. 23

• Snow ends early in the morning, then cloudy with a 40% chance of flurries

• Risk of freezing drizzle early in the morning

• Wind: west 30 km/h gusting to 50

• High: -3°C, but temperatures fall to -11°C in the afternoon

• Wind chill: about -10 in the morning, dropping to around -19 in the afternoon

• UV Index: 1 (low)

Tuesday Night

Clear, with colder air settling in. Low: -18°C.

Wednesday, Dec. 24

A mix of sun and cloud. High: -4°C.
Night: cloudy, low: -9°C.

Thursday, Dec. 25 (Christmas Day)

Cloudy with a 30% chance of flurries. High: -1°C.
Night: cloudy periods with a 40% chance of flurries, low: -10°C.

Wardrobe Recommendations

• This morning: Dress for a -22 wind chill—parka, insulated boots, toque, and mitts. A neck warmer helps a lot on exposed skin.

• Tonight into Tuesday morning: Plan for slippery conditions (snow plus freezing drizzle risk). Waterproof footwear with strong tread is the move.

• Tuesday afternoon: The combination of falling temperatures and gusty west wind will feel like the cold is “switching back on.” Add a windproof layer and tighten up gaps around cuffs/hood.

Weather Trivia

Thunder Bay’s seasonal normals for this time of year are a daily high near -7°C and a nighttime low near -18°C—so today’s -4°C high is milder than average, even if it doesn’t feel that way at sunrise. Also: sunrise is about 8:46 AM and sunset around 5:05 PM, which helps explain why temperatures can drop quickly after late afternoon.

The Last Word on the Weather:
Thunder Bay weather for Monday, December 22, 2025: mostly cloudy and -16°C this morning with a wind chill near -22. Overcast today with a high of -4°C. Snow begins near midnight (2–4 cm) with a freezing drizzle risk. Tuesday turns windy with west gusts to 50 km/h, a chance of flurries, and temperatures falling to -11°C in the afternoon.