A very active stretch of weather is expected across Ontario this week, with strong winds, snow, blowing snow, ice, heavy rain, and extreme cold all making appearances. Below is a day-by-day breakdown summary based on the latest Environment Canada forecast.

Tuesday, December 16:

- Strong southwest winds gusting up to 70 km/h for areas northeast of Lake Superior, Lake Huron and Georgian Bay, including parts of Manitoulin Island.

- Risk of flash freeze in northwestern Ontario as temperatures drop quickly, creating hidden ice on roads and walkways.

- Winds ease by late Tuesday night into early Wednesday.

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Wednesday, December 17:

- Significant wind chills near -40°C in far northwestern Ontario.

- Strong winds along the northeastern shores of Lake Erie and Lake Ontario, with gusts up to 80 km/h.

- Brief burst of snow and blowing snow across northeastern Ontario as a cold front sweeps through.

- Snow spreads into northwestern Ontario later in the day and continues overnight.

Thursday, December 18:

- Strengthening low-pressure system brings 20–30 cm of heavy snow north of Lake Superior toward the Quebec border.

- Additional 5–15 cm of snow across northern Ontario.

- 15–25 mm of rain in southern Ontario on frozen ground, increasing localized flooding risk.

- Rain transitions to snow Thursday evening as temperatures fall.

- Extreme wind chills near -45°C in far northwestern Ontario.

Friday, December 19:

- A flash freeze risk across southern Ontario during the morning commute as temperatures plunge.

- Snow squalls east of Lake Huron and Georgian Bay may deliver 5‑15 cm of snow and create near-zero visibility at times.

- Additional 5‑10 cm of snow possible across northeastern Ontario.

- Extreme wind chills of -40 to -45°C persist across northwestern and far northern Ontario.

- Continued risk of frostbite and hypothermia due to the bitter cold in the northwest.

Long story slightly longer, a prolonged stretch of active weather is expected with high winds, snow, flash freezing, rain and extreme cold affecting different parts of Ontario. Stay safe and warm, everyone and make sure to download our free app InstantWeather to get the most up-to-date, detailed forecast for your specific location.