Canada may be heading into a very unusual winter.

As of September 9, 2026, El Niño is strengthening rapidly in the tropical Pacific, and current forecasts suggest it could become one of the strongest El Niño events observed in the modern record.

NOAA’s Climate Prediction Center says there is a greater than 90% chance of a very strong El Niño during the fall and winter of 2026–27. Its August outlook assigns essentially a 100% probability of El Niño conditions continuing through December, January and February. NOAA has also estimated a 69% chance that the event could reach a level exceeding previous El Niño events in its record dating back to 1950.

That does not mean meteorologists can tell us today how much snow will fall in Toronto on January 18 or whether Winnipeg will escape a January cold snap.

What El Niño can do is change the odds.

And this year, those odds currently point toward a winter that could be considerably milder than normal across much of Canada, with some regions also seeing significant changes in precipitation, snowpack and ice cover.

What exactly is El Niño?

El Niño begins thousands of kilometres away from Canada in the tropical Pacific Ocean.

Normally, trade winds push warm surface water westward across the Pacific. During El Niño, those winds weaken or change, allowing unusually warm water to spread eastward.

That enormous area of warmer ocean changes where heat and moisture enter the atmosphere.

The result can be changes to atmospheric circulation and the jet stream across much of the Northern Hemisphere.

Environment and Climate Change Canada explains that Canada tends to experience the strongest El Niño effects during winter and spring, with western, northwestern and central Canada historically experiencing milder conditions.

Canada’s recently released Changing Climate Report similarly notes that El Niño tends to shift warm southern air northward into western and central Canada and has historically produced warmer winter conditions and, in many areas, reduced precipitation.

The current Canadian winter forecast

Environment and Climate Change Canada’s seasonal forecast for December 2026 through February 2027 currently favours above-normal temperatures across almost the entire country.

The signal is particularly strong across Western Canada.

For example, Environment Canada’s current forecast gives Vancouver a 90–100% probability category for above-normal temperatures. Calgary is in the 80–89% category, Regina 70–79% and Winnipeg 80–89%.

The warm signal continues eastward.

Toronto currently falls in the 50–59% probability category for above-normal winter temperatures, Ottawa is 70–79%, Montreal is 70–79%, and Halifax is 70–79%.

That doesn’t mean every day will be warmer than average.

An El Niño winter can still produce Arctic outbreaks, snowstorms and periods of bitter cold.

The seasonal forecast simply means that when all three winter months are averaged together, warmer conditions are currently more likely.

British Columbia

British Columbia could experience one of the clearest El Niño signals.

Much of the province is expected to be warmer than normal.

Precipitation is more complicated. Vancouver currently has a roughly normal overall winter precipitation signal, while numerous interior locations are tilted toward below-normal precipitation.

That distinction is important.

Rain falling at lower elevations does not necessarily translate into adequate mountain snow.

A warmer winter could raise the snowline and cause storms that historically produced mountain snow to produce rain at lower elevations instead.

That makes the mountain snowpack one of the biggest environmental issues to watch this winter.

Alberta and Saskatchewan

The Prairie provinces may also have a noticeably different winter.

Calgary currently has a strong above-normal temperature signal while Environment Canada’s precipitation forecast favours below-normal precipitation. Regina shows a similar combination of warmer and drier conditions.

That could mean fewer prolonged stretches of extreme cold, although major Arctic outbreaks remain possible.

The environmental concern would be entering spring with insufficient snow accumulation.

Snow is not simply an inconvenience that has to be plowed.

Across agricultural regions, it represents an important portion of the water that eventually enters soils, streams, wetlands and reservoirs.

Manitoba

Winnipeg currently has an 80–89% probability category for above-normal winter temperatures and a strong below-normal precipitation signal.

If that combination persists, parts of Manitoba could see reduced winter snow accumulation.

Again, that doesn’t rule out blizzards.

A region can receive a major snowstorm and still finish the entire winter with below-normal precipitation.

Ontario

Ontario’s forecast is particularly interesting because conditions could vary considerably within the province.

Southern Ontario — including Windsor, London, Simcoe and Toronto — is currently tilted warmer than normal.

Total winter precipitation around Toronto, London and parts of southwestern Ontario is generally forecast to be near normal rather than dramatically dry.

Northern and Great Lakes locations show a stronger tendency toward below-normal precipitation. Wiarton, North Bay, Sudbury and Sault Ste. Marie are among locations showing a dry signal.

Ottawa is different again, with the current model favouring above-normal precipitation.

For Southern Ontario, therefore, the most realistic description may be:

Milder overall, but still capable of producing snowstorms, freezing rain, rain-to-snow events and sudden cold outbreaks.

A mild Ontario winter doesn’t necessarily mean little snow

This is where the Great Lakes become important.

Warmer winters generally produce less Great Lakes ice.

But an open lake can actually provide more moisture for lake-effect snow when sufficiently cold air suddenly arrives.

Lake-effect snow develops when cold, dry air travels across relatively warm, unfrozen water, picking up heat and moisture before depositing that moisture as snow downwind.

So areas east and southeast of Lakes Huron and Superior — and communities affected by Georgian Bay and Lake Erie snow squalls — could still experience major local snow events even during an otherwise mild winter.

That’s one of the apparent contradictions of a warm Great Lakes winter:

Less ice can sometimes help create more intense lake-effect snow when Arctic air does arrive.

Quebec

Quebec currently shows a strong warm signal as well.

Montreal and Quebec City are both forecast to have above-normal winter temperatures, while much of southern Quebec currently leans toward above-normal precipitation.

That combination could increase the frequency of mixed precipitation events where temperatures hover around freezing.

Instead of every winter storm arriving as snow, some could produce combinations of rain, freezing rain, ice pellets and snow.

Atlantic Canada

El Niño historically has a weaker direct influence over Atlantic Canada than over Western and Central Canada.

Nevertheless, the current Environment Canada forecast favours above-normal temperatures across much of the Atlantic region.

Halifax currently falls in the 70–79% above-normal temperature category while precipitation is tilted above normal. Similar wet signals appear in New Brunswick and other portions of the region.

The exact location of the Atlantic storm track will ultimately determine whether individual systems arrive primarily as snow, rain or mixtures of both.

What could this winter mean for Canada’s environment?

The environmental effects of an unusually strong El Niño could ultimately be more important than whether Canadians have to shovel their driveways a few fewer times.

Less mountain snow could affect summer water supplies

One of the most important areas to watch is the mountain snowpack of British Columbia and Alberta.

Snow accumulated during winter acts like a natural reservoir.

It stores water for months before gradually releasing it during spring and early summer.

If warmer temperatures cause more winter precipitation to fall as rain, or if total precipitation is reduced, the spring snowpack can decline.

That can contribute to earlier spring runoff and reduced water availability later in summer.

Agriculture and Agri-Food Canada has previously identified early snowmelt and reduced water supplies as important contributors to drought conditions in Western Canada.

That makes the 2026–27 snowpack particularly important to monitor.

A relatively comfortable winter could create problems months later if insufficient snow remains in the mountains to supply rivers, reservoirs, irrigation systems and ecosystems during the summer of 2027.

Great Lakes ice could be significantly reduced

A strong warm winter would also increase the likelihood of below-normal ice formation on the Great Lakes.

Temperature is one of the primary controls on Great Lakes ice.

Lake Erie normally develops the greatest ice coverage because it is shallow, while deep Lake Ontario normally has the least. Environment and Climate Change Canada’s climate normals show Lake Erie reaching a median maximum coverage of roughly 85%, compared with only about 14% for Lake Ontario.

An El Niño winter doesn’t guarantee record-low ice.

Individual Arctic outbreaks can freeze large areas surprisingly quickly.

But persistent mild conditions make extensive and long-lasting ice less likely.

Less ice can expose Great Lakes shorelines

Lake ice does more than provide a place to fish.

It can protect shorelines from wave action during winter storms.

When the lakes remain open, strong winter winds can continue generating large waves.

NOAA notes that shoreline ice can act as a barrier protecting coastal areas from erosion and flooding. With little ice present, shorelines and infrastructure become more exposed to storm damage.

For communities along Lakes Erie, Huron, Superior and Ontario, that is an environmental consequence worth watching closely.

Great Lakes ecosystems may also notice the difference

Winter ice is part of the Great Lakes ecosystem.

Canadian research notes that ice helps reduce wave energy and protect shallow spawning areas, while NOAA has pointed to evidence that ice provides protection for species such as whitefish and helps regulate biological processes within the lakes.

One mild winter is not going to fundamentally transform the Great Lakes.

But unusually low ice can change the physical environment experienced by fish, coastal wetlands and shoreline habitats.

Freeze-thaw cycles could become more important

Warmer does not necessarily mean consistently warm.

In regions such as Southern Ontario, temperatures may repeatedly move above and below freezing.

That produces freeze-thaw cycles.

Water enters soil, pavement and small cracks during mild periods and freezes again when colder weather returns.

For agriculture, winter crops and perennial plants can also be affected when unusually warm weather interrupts winter dormancy or reduces protective snow cover.

Ontario agricultural guidance notes that mild winter or early-spring warming can push fruit-bud development ahead of schedule, leaving blossoms more vulnerable if freezing temperatures subsequently return.

So an early spring is not automatically good news for farmers.

Reduced snow cover can change soil conditions

Snow also acts as insulation.

A deep snowpack can keep soil temperatures relatively stable even when the air becomes extremely cold.

With less snow, exposed soils and plant roots can experience larger temperature swings.

A winter with repeated thaws can therefore create a strange situation in which average air temperatures are warmer while some vegetation experiences additional stress from alternating thawing and freezing.

Some agricultural pests may survive the winter more successfully

There is another consequence of warmer winter temperatures that farmers increasingly have to consider.

Cold winters kill or suppress some insects and plant diseases.

Agriculture and Agri-Food Canada says milder winters can improve the overwinter survival of some pests and diseases, potentially increasing pressure during the following growing season.

That does not mean Canada will experience an insect outbreak next spring.

It means winter mortality could be lower for certain species, making spring monitoring more important.

Ontario farmers already see this relationship with certain crop pests. Provincial agricultural guidance notes that harsh winters can substantially reduce some insect populations.

Spring flooding could either decrease — or become more complicated

Normally, large winter snowpacks create the potential for significant spring runoff.

A low-snow El Niño winter could reduce that risk in some regions.

But precipitation type matters.

Rain falling onto frozen ground, rapid snowmelt during an unusual winter warm spell, or rain combined with an existing snowpack can still produce flooding.

The timing may therefore change even if total winter precipitation does not.

Wildlife will experience the winter differently too

A mild winter can benefit some wildlife by reducing the energy required to survive prolonged extreme cold and making food easier to access.

But environmental effects are rarely universally positive.

Species adapted to persistent snow and ice may lose habitat, while freeze-thaw cycles can create hard crusts over snow or change access to vegetation.

Aquatic species can also experience different conditions when lakes and rivers remain open longer.

The effect will vary substantially by species and region.

Could Canada still get a major winter storm?

Absolutely.

This may be the most important point in the entire forecast.

El Niño predicts tendencies, not individual weather events.

Even during an exceptionally warm winter, Canada remains Canada.

Arctic air will still exist.

Snowstorms will still develop.

Ontario can still experience snow squalls.

Quebec can still experience major winter storms.

The Prairies can still experience dangerous cold.

Atlantic Canada can still get powerful nor’easters.

A winter that averages two or three degrees warmer than normal can still contain several brutally cold weeks.

Seasonal forecasting tells us which way the scales are leaning — not exactly what weather will occur on any particular day.

The bigger story may not be how warm the winter feels

If the current forecasts hold, the winter of 2026–27 could become an important Canadian weather story.

A powerful El Niño may deliver a relatively mild winter to millions of Canadians.

For people paying heating bills or clearing snow, that might sound welcome.

But the environmental consequences are more complicated.

Western Canada will be watching mountain snowpack and water supplies.

Prairie farmers will be watching winter precipitation and soil moisture.

Great Lakes communities will be watching ice formation, shoreline exposure and lake-effect snow.

Ontario farmers will be watching freeze-thaw cycles and overwintering pests.

And across the country, scientists will be watching how one of the potentially strongest El Niño events in decades interacts with Canada’s already warming climate.

The important thing is not to interpret “warmer winter” as “no winter.”

Canada will still see cold, snow, ice and dangerous storms.

What may change is how often they happen, how long they last, where storms travel and whether winter precipitation arrives as snow, rain or ice.

And the consequences could continue long after the last snow disappears in the spring of 2027.

Verified primary and government sources

Environment and Climate Change Canada — El Niño Environment Canada El Niño information

Environment and Climate Change Canada — Seasonal Forecasts Canadian seasonal forecasts

NOAA Climate Prediction Center — ENSO Diagnostic Discussion NOAA ENSO Diagnostic Discussion

NOAA Climate Prediction Center — Official ENSO Probabilities NOAA ENSO probabilities

Environment and Climate Change Canada — Great Lakes Ice Climate Normals Great Lakes ice climate normals

Agriculture and Agri-Food Canada — Climate Change Impacts on Agriculture AAFC agriculture climate impacts