Almost the entire nation 🇨🇦will be colder than -10°F with wind chills colder than -80°F.

1. What the national averages actually show — populated south is much milder

Climate and travel-data sites that aggregate December averages for Canadian cities show typical lows in southern population centres well above −23°C (−10°F). Toronto’s December average low is about −2.5°C (27.5°F) and many southern city averages cluster around −1°C to −6°C (≈30°F–20°F) rather than anywhere near −23°C ^{[3] [1] [2]}.

2. Where extreme cold does occur — the Arctic and interior can be brutal

Specialized climate summaries note that Canada’s Arctic islands and the central-northern interior routinely reach very low temperatures in winter; daily averages below −25°C (−13°F) are common in large northern areas and “during cold waves” temperatures can drop below −40°C (−40°F) across large central-northern regions ^[4]. Sources list record and average extreme minima down to about −20.5°C (−5°F) in some datasets, underscoring strong regional variation ^[5].

3. Wind chill claims — no broad-source evidence for −80°F across Canada

The specific figure of wind chills colder than −80°F (about −62°C) is not documented in the provided sources as a nationwide forecast or typical event. While the combination of very low air temperatures and strong winds can produce extreme wind chill values in isolated Arctic or exposed interior locations, the aggregated December guides and city averages cited here do not report countrywide wind chills at that magnitude ^{[4] [6] [5]}. Available sources do not mention a national forecast of wind chills near −80°F.

4. Seasonal nuance — averages versus episodic cold waves

Multiple sources stress that December climate in Canada varies sharply by region: coastal British Columbia is comparatively mild and wet, the southern interior and Great Lakes region are cold but far from Arctic extremes, and the far north is routinely frigid ^{[4] [7]}. Websites relying on long-term averages show typical December temperatures over the country ranging from mild single digits Celsius in pockets up to −25°C or lower in the far north — meaning a single headline about “almost the entire nation” obscures this spatial complexity ^{[6] [8]}.

5. How to interpret sensational phrasing — hidden agendas and context

Phrases like “almost the entire nation” and raw numbers in Fahrenheit are attention-grabbing and can imply nation‑wide emergency conditions that do not match averaged climate data. Sources used here are travel and climate summaries and do note possible severe cold waves in northern/central regions ^{[4] [9]}, but they do not support blanket, country‑wide forecasts of −10°F air temps and −80°F wind chills for most Canadians ^{[3] [1]}. This mismatch suggests the original claim is either a misinterpretation of extreme localized model output or deliberate hyperbole.

6. Practical takeaway — who is actually at risk

Residents and travellers in the Arctic and central-northern interior should plan for extreme cold, sometimes dropping below −40°C (−40°F), and take wind chill warnings seriously ^[4]. People in southern urban areas (Toronto, Montreal, most populated corridors) face much milder December averages, typically around freezing to single-digit negative Celsius nights, according to multiple city and national summaries ^{[3] [10] [1]}. For precise safety guidance, consult regional meteorological agencies rather than country‑wide summaries.

Limitations: these conclusions are drawn from the provided climate- and travel‑data sources and city averages; they do not include real‑time forecasts or model runs that might produce short‑lived, localized extreme wind‑chill projections. Available sources do not mention a contemporaneous national forecast of “almost the entire nation” below −10°F with wind chills below −80°F ^{[6] [4]}.