Seeing is Believing: Temperature Records Prove Canada is Warming

A whole generation of Canadians has never experienced what was considered a “normal” Canadian climate for most of modern history. Historical records show that every year since 1998 – that’s 20 years ago now – has been warmer than the 20th century average.

The images below illustrate historical Canadian climate data back to 1898 (Data & Methods). The average temperature of each season and year is compared to 20th century seasonal and annual averages: blue shows cooler than average values, and red shows warmer than average.

The image shows a clear and dramatic transition from cooler to warmer temperatures – from blue to red – as the years go by.

We have a wealth of historical measurement records about Canada’s climate. They reveal these key facts:

  1. Canada’s climate is warming.
  2. The warming trend began decades ago.
  3. Most years have been warmer than average since the mid 1970s.
  4. All of the past 20 years have been above average.

Climate change is too often talked about as though it’s a remote threat in the distant future. Well, Canada’s historical temperature record shows that climate change is already happening, right here and right now. Canadians are now living with a climate that’s warmer than was considered “normal” for four generations

 

The large version below shows the numerical values, and you can click through to an even larger version.

 


Steve McCullough & Ryan Smith

Prairie Climate Centre

The Prairie Climate Centre is committed to making climate change meaningful and relevant to Canadians. We explain and communicate climate change through maps, videos, reports, and web content like this. Sign up for our mailing list to stay informed about our work and about new developments in climate change science and policy. Help us move Canada from climate risk to resilience.


Data & methods

These graphics were creating using observed mean temperature data from Environment and Climate Change Canada. The annual and seasonal temperature anomalies for each station were first computed individually (using a 1901-2000 baseline period) and then the average for all of Canada was computed by simply averaging these individual values. Importantly, we only included stations in this analysis that had at least 50 years of 20th century data. Click here to see a graph showing the number of stations reporting per year.

The federal “Historical Climate Data” archive contains measurements and observations going back as far as 1840. Scientists have used this data to produce a high-quality historical record of monthly averages that describe Canada’s climate. We start with 1898 because there was no Arctic data available before this year.