Climate Change

How Canada’s climate has warmed: the national record, the faster-warming North, and long-run temperatures for recognizable cities

Canada is warming faster than the world as a whole, and its northern regions are warming faster than the southern parts of the country. The temperatures here are drawn from Environment and Climate Change Canada’s homogenized climate records. These are adjusted for station moves, instrument changes, and other factors that are unrelated to physical conditions. This ensures that long-term trends are comparable and can be expressed as departures from the 1961–1990 reference period (the standard baseline). They provide direct observations of change.

A warming country

The national average temperature has risen since records began in 1948. Each bar is one year’s departure from the 1961–1990 average. Red is above average, blue is below. The early decades are mostly blue; recent years are almost entirely red. 2024 and 2010 tied for the warmest year on record, at about +3.1 °C above the reference period.

Mapped: where it’s warm, cold, and changing

Canada’s temperature varies enormously by place and season. The full picture lives on its own interactive, hover-able page. This includes the typical temperature for any month, how the recent months compare to normal (has it been unusual lately?), and how much each region has warmed:

Explore maps of Canada’s temperatures →

The North is warming fastest

Warming is not even across the country. The bars below are Environment and Climate Change Canada’s 11 climate regions. These are broad areas covering the whole country, each shown as the average of its weather stations (homogenized, then interpolated to a grid and averaged over the region), not a single location. Over 1948–2024 the far-northern regions have warmed roughly twice as fast as the southern and Atlantic ones. This is a pattern known as Arctic amplification. It is driven partly by the loss of reflective snow and sea ice. The fastest-warming areas are the Mackenzie Valley (the forested Northwest Territories), Yukon and northern B.C., and the mainland Arctic tundra. Atlantic Canada, the eastern boreal, and the Pacific coast have warmed least. The dashed line is the national average; ECCC’s Climate Trends and Variations Bulletin maps the exact region boundaries.

Where the regions are

Each marker sits at a region’s approximate centre (these are areas, not points), coloured by the same warming rate as the bars above. The warm reds cluster across the North. Hover for the rate; the bar chart above has the exact figures.

Long-run temperatures, city by city

Some Canadian temperature records are quite long. Toronto’s dataset reaches back to 1841 (pre-Confederation, when responsible government was still emerging). Use the dropdown to switch cities. Each chart shows two series that are deliberately kept separate, not spliced: the homogenized record (the trend-quality series, which the open national dataset currently carries to 2020) and a raw recent tail computed from current daily observations.

The Arctic stations tell their own story. Eureka and Alert begin in 1948 and 1951. There are no earlier instrumental records that far north. The first permanent High Arctic weather stations were not built until the 1947–1950 Joint Arctic Weather Stations program.

Warming by season

Warming isn’t spread evenly across the year. In much of the country the cold seasons have warmed most. Cities near the ocean coasts and the Great Lakes (Toronto, Vancouver) warm more evenly across the seasons. Each season’s warming rate over its homogenized record (°C per century) is shown in the legend, for either the seasonal average temperature or the average daytime high. The daytime high has generally warmed a little less than the overall average.

Warming spirals: south vs. Arctic

The famous climate spirals (NASA, Ed Hawkins) keep every month of data and still look smooth because they average the whole globe. A single station can’t be that smooth, so these two, Toronto and Eureka on the same scale, keep the full month-to-month detail and stay deliberately jagged. (The two illustrative examples were chosen for their data records: Toronto holds one of the country’s longest continuous series, and Eureka is among the High Arctic’s most complete.) Each month sits at its position around the circle; the further out, the further above the 1961–1990 average (the green ring is that normal; faint rings every 4 °C). Each year is one coloured loop — blue if the year ran below normal, red if above. Press ▶ to build either up year by year. Eureka’s loops swing far wider and redden far harder than Toronto’s: Arctic amplification you can see.

Same scale on both, 1948 onward (when the Arctic stations begin). Full monthly anomalies (no smoothing) from the homogenized record (to 2020); the green ring is the 1961–1990 normal; each loop is coloured by that year’s average departure. Source: ECCC AHCCD, via the GeoMet API.

Download data

Homogenized vs. raw. A homogenized record (AHCCD) has been adjusted to remove the effects of station relocations, instrument changes, and changes in observing practice, so that the remaining year-to-year change reflects climate rather than the measurement setup. It is the right series for trends, but ECCC’s openly published version currently ends in 2020. The raw recent tail is the unadjusted annual mean from current daily observations — current to last year, but not directly comparable to the homogenized series, which is why the two are drawn as separate lines.

Baselines. Departures are measured against the 1961–1990 average, the standard reference period used by ECCC and the World Meteorological Organization. A positive departure means warmer than that baseline.

Arctic records. The High Arctic has no instrumental record before the late 1940s; Alert (1950) and Eureka (1947) were among the first permanent stations, built under the Joint Arctic Weather Stations program. All data are published under the Open Government Licence – Canada.