Thunder Bay – Weather Desk – Sioux Lookout starts Monday under mainly clear skies, but don’t let the sunshine fool you—winter is lining up a quick change. Snow moves in this evening, with 5 to 10 cm expected and a risk of freezing drizzle overnight, followed by strong west winds gusting to 50 km/h. Travel and outdoor plans will need a little extra care, especially with frostbite risk in the morning wind chill.

Today’s Weather Overview

Current Conditions (Sioux Lookout Airport — 5:00 AM CST)

At 5:00 AM CST, Sioux Lookout Airport reported mainly clear skies and -18.7°C (about -2°F). Pressure was 102.5 kPa and rising, humidity 79%, and visibility an excellent 24 km. A light ENE wind at 9 km/h pushed the wind chill to -25.

Today (Monday, Dec. 22)

Expect a sunny start, becoming a mix of sun and cloud this morning. Winds stay light (up to 15 km/h), but it’s still a cold one: wind chill near -31 this morning, easing to around -14 this afternoon. The high reaches -10°C (14°F), and Environment Canada flags a risk of frostbite during the coldest wind chill period. Tonight

Cloud thickens up, and snow begins this evening. Watch for freezing drizzle overnight, which can create slick “invisible ice” on untreated roads and sidewalks. Snowfall is forecast at 5 to 10 cm. Winds turn west 30 km/h with gusts to 50 overnight, adding blowing snow to the mix. Low -16°C (3°F), with wind chill near -24 overnight.

Tomorrow’s Forecast

Expected Conditions (Next 3 Days)

Tuesday, Dec. 23

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

• Risk of freezing drizzle in the morning

• Wind: W 30 km/h gusting to 50, becoming light late afternoon

• High -12°C (10°F)

• Wind chill: -27 in the morning, around -17 in the afternoon

Tuesday Night

• Clear

• Low -21°C (-6°F)

Wednesday, Dec. 24

• A mix of sun and cloud

• High -10°C (14°F)

• Night: cloudy, low -15°C (5°F)

Thursday, Dec. 25 (Christmas Day)

• Cloudy with a 40% chance of snow

• High -7°C (19°F)

• Night: cloudy periods, 40% chance of snow, low -17°C (1°F)

Wardrobe Recommendations

• This morning: Full winter gear—insulated coat, snowpants for long outdoor time, and a face covering (wind chills near -31 can be harsh on exposed skin).

• Tonight into Tuesday: Waterproof boots with good tread and traction if you have it. Freezing drizzle + fresh snow is a classic slip-and-slide setup.

• Wind night: With gusts near 50 km/h, a snug hat/hood and mitts matter more than you think—wind finds gaps fast.

• Driving tip: Plan extra braking distance tonight and Tuesday morning, and keep a small winter kit in the vehicle (gloves, toque, blanket).

Weather Trivia

Sioux Lookout’s cold can get truly legendary: Environment Canada climate data lists an extreme minimum temperature of -46.1°C, recorded on February 18, 1966.

The Last Word on the Weather:
Sioux Lookout weather for Monday, Dec. 22, 2025: mainly clear early, then a mix of sun and cloud with a high of -10°C and morning wind chill near -31 with frostbite risk. Snow begins this evening (5–10 cm) with freezing drizzle risk and west winds gusting 50 km/h overnight.