Alberta

• Dates: August 25 to August 31, 2025
• Peak daily high temperature during the heat wave: 28.8 °C
• Degrees above normal daily high temperature: 9.3 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Fort Smith, Northwest Territories

• Dates: August 24 to August 31, 2025
• Peak daily high temperature during the heat wave: 25.5 °C
• Degrees above normal daily high temperature: 11.6 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Southern British Columbia

• Dates: August 23 to September 7, 2025
• Peak daily high temperature during the heat wave: 27.1 °C
• Degrees above normal daily high temperature: 10.3 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Northern British Columbia

• Dates: August 23 to September 9, 2025
• Peak daily high temperature during the heat wave: 23.5 °C
• Degrees above normal daily high temperature: 9.6 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Atlantic Canada

• Dates: August 7 to August 14, 2025
• Peak daily high temperature during the heat wave: 28.4 °C
• Degrees above normal daily high temperature: 9.6 °C
• Statement of likelihood: The event was far more likely because of human influence on the climate.

Southern Quebec

• Dates: August 7 to August 13, 2025
• Peak daily high temperature during the heat wave: 29.3 °C
• Degrees above normal daily high temperature: 9.1 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Northern Quebec

• Dates: August 6 to August 9, 2025
• Peak daily high temperature during the heat wave: 23.8 °C
• Degrees above normal daily high temperature: 7.0 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Fort Smith, Northwest Territories

• Dates: July 30 to August 1, 2025
• Peak daily high temperature during the heat wave: 25.2 °C
• Degrees above normal daily high temperature: 6.0 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Atlantic Canada

• Dates: July 10 to 15, 2025
• Peak daily high temperature during the heat wave: 25.6 °C
• Degrees above normal daily high temperature: 7.1 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Northern Quebec

• Dates: July 10 to 13, 2025
• Peak daily high temperature during the heat wave: 24.2 °C
• Degrees above normal daily high temperature: 7.5 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Yukon

• Dates: June 20-23, 2025
• Peak daily high temperature during the heat wave: 22.0 °C
• Degrees above normal daily high temperature: 6.5 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Alberta

• Dates: May 28-31, 2025
• Peak daily high temperature during the heat wave: 28.8 °C
• Degrees above normal daily high temperature: 11.3°C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Eastern Ontario

• Dates: September 11 to September 21, 2024
• Peak daily high temperature during the heat wave: 25.9 °C
• Degrees above normal daily high temperature: 7.9 °C
• Statement of likelihood: The event was more likely because of human influence on the climate.

Fort Smith

• Dates: September 6 to September 8, 2024
• Peak daily high temperature during the heat wave: 19.0 °C
• Degrees above normal daily high temperature: 7.3 °C
• Statement of likelihood: The event was more likely because of human influence on the climate.

Northern Qikiqtaaluk

• Dates: September 10 to September 14, 2024
• Peak daily high temperature during the heat wave: 0.4 °C
• Degrees above normal daily high temperature: 5.8 °C
• Statement of likelihood: The event was more likely because of human influence on the climate.

Northern Quebec

• Dates: September 14 to October 3, 2024
• Peak daily high temperature during the heat wave: 20.6 °C
• Degrees above normal daily high temperature: 10.6 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Saskatchewan

• Dates: September 7 to September 10, 2024
• Peak daily high temperature during the heat wave: 28.5 °C
• Degrees above normal daily high temperature: 11.2 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Southern British Columbia

• Dates: September 4 to September 8, 2024
• Peak daily high temperature during the heat wave: 24.8 °C
• Degrees above normal daily high temperature: 8.8 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Southern Qikiqtaaluk

• Dates: September 20 to October 16, 2024
• Peak daily high temperature during the heat wave: 8.8 °C
• Degrees above normal daily high temperature: 10.2 °C
• Statement of likelihood: The event was far more likely because of human influence on the climate.

Southern Quebec

• Dates: September 15 to September 20, 2024
• Peak daily high temperature during the heat wave: 23.6 °C
• Degrees above normal daily high temperature: 8.9 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Western Ontario

• Dates: September 13 to September 21, 2024
• Peak daily high temperature during the heat wave: 24.9 °C
• Degrees above normal daily high temperature: 10.1 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Atlantic Canada

• Dates: August 24 to August 27, 2024
• Peak daily high temperature during the heat wave: 23.9 °C
• Degrees above normal daily high temperature: 6.7 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Eastern Ontario

• Dates: July 31 to August 2, 2024
• Peak daily high temperature during the heat wave: 29.2 °C
• Degrees above normal daily high temperature: 5.8 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Fort Smith

• Dates: August 8 to August 13, 2024
• Peak daily high temperature during the heat wave: 26.9 °C
• Degrees above normal daily high temperature: 9.2 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Inuvik

• Dates: August 6 to August 10, 2024
• Peak daily high temperature during the heat wave: 26.5 °C
• Degrees above normal daily high temperature: 13.0 °C
• Statement of likelihood: The event was far more likely because of human influence on the climate.

Kitikmeot

• Dates: August 7 to August 12, 2024
• Peak daily high temperature during the heat wave: 25.0 °C
• Degrees above normal daily high temperature: 12.4 °C
• Statement of likelihood: The event was far more likely because of human influence on the climate.

Kivalliq

• Dates: August 8 to August 14, 2024
• Peak daily high temperature during the heat wave: 27.1 °C
• Degrees above normal daily high temperature: 12.2 °C
• Statement of likelihood: The event was far more likely because of human influence on the climate.

Manitoba

• Dates: July 30 to August 1, 2024
• Peak daily high temperature during the heat wave: 28.3 °C
• Degrees above normal daily high temperature: 6.4 °C
• Statement of likelihood: The event was more likely because of human influence on the climate.

Northern British Columbia

• Dates: August 7 to August 11, 2024
• Peak daily high temperature during the heat wave: 23.6 °C
• Degrees above normal daily high temperature: 7.0 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Northern Quebec

• Dates: August 13 to August 16, 2024
• Peak daily high temperature during the heat wave: 23.6 °C
• Degrees above normal daily high temperature: 7.8 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Southern Quebec

• Dates: July 27 to August 3, 2024
• Peak daily high temperature during the heat wave: 28.3 °C
• Degrees above normal daily high temperature: 7.6 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Yukon

• Dates: August 5 to August 9, 2024
• Peak daily high temperature during the heat wave: 24.1 °C
• Degrees above normal daily high temperature: 8.9 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Atlantic Canada:

• Dates: July 28 to July 31, 2024
• Peak daily high temperature during the heat wave: 26.1 °C
• Degrees above normal daily high temperature: 6.7 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Alberta:

• Dates: July 7 to 11, 2024
• Peak daily high temperature during the heat wave: 31.5 °C
• Degrees above normal daily high temperature: 9.8 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Fort Smith:

• Dates: July 15 to July 20, 2024
• Peak daily high temperature during the heat wave: 28.4 °C
• Degrees above normal daily high temperature: 9.2 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Northern British Columbia:

• Dates: July 17 to 22, 2024
• Peak daily high temperature during the heat wave: 24.2 °C
• Degrees above normal daily high temperature: 7.2 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Northern Quebec:

• Dates: July 28 to 30, 2024
• Peak daily high temperature during the heat wave: 24.2 °C
• Degrees above normal daily high temperature: 7.0 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Southern British Columbia:

• Dates: July 14 to 22, 2024
• Peak daily high temperature during the heat wave: 29.2 °C
• Degrees above normal daily high temperature: 9.2 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Saskatchewan:

• Dates: July 17 to 22, 2024
• Peak daily high temperature during the heat wave: 30.9 °C
• Degrees above normal daily high temperature: 8.0 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Western Ontario:

• Dates: July 26 to July 28, 2024
• Peak daily high temperature during the heat wave: 27.9 °C
• Degrees above normal daily high temperature*: 6.1 °C
• Statement of likelihood: The event was more likely because of human influence on the climate.

Yukon:

• Dates: July 21 to July 26, 2024
• Peak daily high temperature during the heat wave: 23.0 °C
• Degrees above normal daily high temperature: 6.5 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Atlantic Canada

• Dates: June 18 to 20, 2024
• Peak daily high temperature during the heat wave: 26.1 °C
• Degrees above normal daily high temperature: 10.6 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Eastern Ontario

• Dates: June 17 to 19, 2024
• Peak daily high temperature during the heat wave: 29.0 °C
• Degrees above normal daily high temperature: 7.4 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Fort Smith

• Dates: June 29 to July 1, 2024
• Peak daily high temperature during the heat wave: 24.9 °C
• Degrees above normal daily high temperature: 6.7 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Inuvik

• Dates: June 28 to 30, 2024
• Peak daily high temperature during the heat wave: 22.0 °C
• Degrees above normal daily high temperature: 7.2 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Kivalliq

• Dates: June 30 to July 2, 2024
• Peak daily high temperature during the heat wave: 22.1 °C
• Degrees above normal daily high temperature: 7.5 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Northern Quebec

• Dates: June 18 to 19, 2024
• Peak daily high temperature during the heat wave: 21.5 °C
• Degrees above normal daily high temperature: 7.2 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Southern Quebec

• Dates: June 18 to 20, 2024
• Peak daily high temperature during the heat wave: 29.5 °C
• Degrees above normal daily high temperature: 10.7 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Yukon

• Dates: June 26 to 30, 2024
• Peak daily high temperature during the heat wave: 21.4 °C
• Degrees above normal daily high temperature: 5.3 °C
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Saskatchewan

• Dates: February 12 – 19, 2025
• Coldest daily temperature: -34.5 °C
• Difference from the normal daily low temperature: -17.2 °C
• Statement of likelihood: The event was much less likely because of human influence on the climate.

Western Ontario

• Dates: January 20 – 21, 2025
• Coldest daily temperature: -34.0 °C
• Difference from the normal daily low temperature: -12.0 °C
• Statement of likelihood: The event was much less likely because of human influence on the climate.

Atlantic Canada

Eastern Labrador-Happy Valley-Goose Bay

• Date: November 01, 2025
• Total accumulated precipitation: 39.9 mm
• Portion of November's average total precipitation: 43 %
• Statement of likelihood: The event was much more likely because of human influence on the climate. 

Western Labrador-Happy Valley-Goose Bay

• Date: November 11, 2025
• Total accumulated precipitation: 25.0 mm
• Portion of November's average total precipitation: 29 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Northern British Columbia

Kitimat-Stikine and Skeena-Queen Charlotte

• Date: October 23, 2025
• Total accumulated precipitation: 48.9 mm
• Portion of October's average total precipitation: 19 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Manitoba

Eastern Churchill/Northern Manitoba

• Date: October 13, 2025
• Total accumulated precipitation: 26.4 mm
• Portion of October's average total precipitation: 42 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Thompson/North Central

• Date: October 13, 2025
• Total accumulated precipitation: 34.2 mm
• Portion of October's average total precipitation: 62 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Southern Qikiqtaaluk, Nunavut

West Central Baffin Island

• Date: October 05, 2025
• Total accumulated precipitation: 15.5 mm
• Portion of October's average total precipitation: 31 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Southern Quebec

Southern Central Québec

• Date: October 31, 2025
• Total accumulated precipitation: 39.1 mm
• Portion of October's average total precipitation: 36 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Saguenay Lac-Saint-Jean

• Date: October 31, 2025
• Total accumulated precipitation: 28.1 mm
• Portion of October's average total precipitation: 27 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Inuvik, Northwest Territories

Northern Inuvik 

• Date: September 06, 2025
• Total accumulated precipitation: 20.5 mm
• Portion of September's average total precipitation: 58 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Northern Qikiqtaaluk, Nunavut

Southern Ellesmere Island 

• Date: September 23, 2025
• Total accumulated precipitation: 10.0 mm
• Portion of September's average total precipitation: 34 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Parry Islands 

• Date: September 23, 2025
• Total accumulated precipitation: 15.1 mm
• Portion of September's average total precipitation: 37 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Northern Quebec

Eastern Rivière-Koksoak 

• Date: September 17, 2025
• Total accumulated precipitation: 24.9 mm
• Portion of September's average total precipitation: 20 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Southwestern Rivière-Koksoak 

• Date: September 17, 2025
• Total accumulated precipitation: 25.6 mm
• Portion of September's average total precipitation: 22 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Northern British Columbia

Stikine 

• Date: August 17, 2025
• Total accumulated precipitation: 16.5 mm
• Portion of August's average total precipitation: 22 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Manitoba

Western Churchill/Northern Manitoba 

• Date: August 14, 2025
• Total accumulated precipitation: 24.1 mm
• Portion of August's average total precipitation: 28 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Fort Smith, Northwest Territories

Western Fort Smith 

• Date: August 05, 2025
• Total accumulated precipitation: 20.6 mm
• Portion of August's average total precipitation: 26 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Inuvik, Northwest Territories

Victoria Island Inuvik 

• Date: August 30, 2025
• Total accumulated precipitation: 21.0 mm
• Portion of August's average total precipitation: 46 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

 Northern Inuvik 

• Date: August 24, 2025
• Total accumulated precipitation: 10.0 mm
• Portion of August's average total precipitation: 24 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Kitikmeot, Nunavut

Central Southeastern Kitikmeot 

• Date: August 08, 2025
• Total accumulated precipitation: 16.6 mm
• Portion of August's average total precipitation: 36 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Northeastern Kitikmeot 

• Date: August 31, 2025
• Total accumulated precipitation: 13.9 mm
• Portion of August's average total precipitation: 30 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Northern Qikiqtaaluk, Nunavut

Southern Ellesmere Island 

• Date: August 25, 2025
• Total accumulated precipitation: 12.5 mm
• Portion of August's average total precipitation: 24 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Western Qikiqtaaluk 

• Date: August 25, 2025
• Total accumulated precipitation: 14.3 mm
• Portion of August's average total precipitation: 29 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Parry Islands 

• Date: August 25, 2025
• Total accumulated precipitation: 9.6 mm
• Portion of August's average total precipitation: 19 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Southern Qikiqtaaluk, Nunavut

Western Baffin Island 

• Date: August 06, 2025
• Total accumulated precipitation: 12.9 mm
• Portion of August's average total precipitation: 25 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Northern Quebec

Northwestern Rivière-Koksoak 

• Date: August 13, 2025
• Total accumulated precipitation: 23.0 mm
• Portion of August's average total precipitation: 27 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Saskatchewan

Central La Ronge 

• Date: August 21, 2025
• Total accumulated precipitation: 30.2 mm
• Portion of August's average total precipitation: 42 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Southern La Ronge 

• Date: August 14, 2025
• Total accumulated precipitation: 24.9 mm
• Portion of August's average total precipitation: 39 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Alberta

Southwestern Alberta 

• Date: July 14, 2025
• Total accumulated precipitation: 22.5 mm
• Portion of July's average total precipitation: 32 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Atlantic Canada

Eastern Labrador-Happy Valley-Goose Bay 

• Date: July 18, 2025
• Total accumulated precipitation: 36.0 mm
• Portion of July's average total precipitation: 33 %
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Kitikmeot, Nunavut

Victoria Island Kitikmeot 

• Date: July 19, 2025
• Total accumulated precipitation: 10.9 mm
• Portion of July's average total precipitation: 31 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Kivalliq, Nunavut

Northwestern Kivalliq 

• Date: July 10, 2025
• Total accumulated precipitation: 18.3 mm
• Portion of July's average total precipitation: 41 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Northern Qikiqtaaluk, Nunavut

Northern Ellesmere Island 

• Date: July 19, 2025
• Total accumulated precipitation: 6.5 mm
• Portion of July's average total precipitation: 20 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Southern Qikiqtaaluk, Nunavut

West Central Baffin Island 

• Date: July 11, 2025
• Total accumulated precipitation: 16.7 mm
• Portion of July's average total precipitation: 27 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Western Baffin Island 

• Date: July 11, 2025
• Total accumulated precipitation: 20.4 mm
• Portion of July's average total precipitation: 41 %
• Statement of likelihood: The event was much more likely because of human influence on the climate.

Yukon

Southeastern Yukon 

• Date: July 24, 2025
• Total accumulated precipitation: 17.6 mm
• Portion of July's average total precipitation: 23 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Alberta

Southeastern Alberta 

• Date: June 21, 2025
• Total accumulated precipitation: 28.1 mm
• Portion of June's average total precipitation: 38 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Southwestern Alberta 

• Date: June 21, 2025
• Total accumulated precipitation: 39.2 mm
• Portion of June's average total precipitation: 41 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Atlantic Canada

Eastern Labrador-Happy Valley-Goose Bay 

• Date: June 21, 2025
• Total accumulated precipitation: 31.0 mm
• Portion of June's average total precipitation: 34 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Fort Smith, Northwest Territories

Eastern Fort Smith 

• Date: June 02, 2025
• Total accumulated precipitation: 27.6 mm
• Portion of June's average total precipitation: 66 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Eastern Ontario

Central Southern Ontario 

• Date: June 19, 2025
• Total accumulated precipitation: 31.5 mm
• Portion of June's average total precipitation: 42 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Southern Quebec

La Haute-Côte-Nord, Manicouagan, and Sept-Rivières 

• Date: June 20, 2025
• Total accumulated precipitation: 29.7 mm
• Portion of June's average total precipitation: 36 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Saskatchewan

Southwestern Saskatchewan 

• Date: June 21, 2025
• Total accumulated precipitation: 21.5 mm
• Portion of June's average total precipitation: 28 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

Northern La Ronge 

• Date: June 01, 2025
• Total accumulated precipitation: 19.7 mm
• Portion of June's average total precipitation: 40 %
• Statement of likelihood: The event was more likely because of human influence on the climate.

On one end of the scale, the extreme weather event was:

• far less likely because of human influence on the climate
• much less likely because of human influence on the climate
• less likely because of human influence on the climate

In the middle:

• no evidence of an attributable change in likelihood for this event

On the other end of the scale, the extreme weather event was:

• more likely because of human influence on the climate
• much more likely because of human influence on the climate
• far more likely because of human influence on the climate

On one end of the scale, if the event was:

• far less likely: at least 10X less likely to have happened
• much less likely: at least 2X to 10X less likely to have happened
• less likely: at least 1X to 2X less likely to have happened due to human influence on the climate

In the middle, if there was:

• no evidence: no change due to human influence on the climate identified

On the other end of the scale, if the event was:

• more likely: at least 1X to 2X more likely to have happened
• much more likely: at least 2X to 10X more likely to have happened
• far more likely: at least 10X more likely to have happened due to human influence on the climate

Climate scientists use the rapid extreme weather event attribution system to compare past and present climates. The image shows how temperature extremes change with climate change.

The image has six different parts:

Left curve (blue): The left curve shows the likelihood of temperatures in a past climate. It begins on the left. It rises to a peak to the right and then falls and ends in a tail

This is based on levels of atmospheric gases that existed before the Industrial Revolution.

Right curve (red): The right curve shows how likely today’s temperatures are. It begins to the right of the blue curve and rises to a peak. It falls and ends in a tail to the right of the blue curve

This is based on current, observed levels of greenhouse gases and other results of human activity.

Scale: Below the red and blue curves, a scale ranges from extreme cold on the far left, average temperatures in the middle, and extreme heat on the right. The left of the scale is for cooler temperatures and the right side of the scale is for hotter temperatures.

Vertical line: The vertical black line shows an observed extreme event. Where the black line is put on the scale shows how strong the event was.

Shaded area (left curve, dotted): The dotted area shows the chance of a heat wave at least as strong as that observed in the past climate.

Shaded area (right curve, diagonal lines): The lined area shows how much more likely a heat wave, at least as strong as that observed, is in our current climate.

Comparing the curves

Comparing the left curve (blue) and the right curve (red) shows that the current climate is warmer than the past climate.

The shaded area for the red curve is larger than the shaded area for the blue curve. This shows that heat waves are more likely to occur in today’s climate than the past.

Map of Canada showing the 17 regions for extreme temperature event attribution analysis. Each number below corresponds to the region for extreme event attribution in Canada.

1. Yukon
2. Inuvik, Northwest Territories 
3. Fort Smith, Northwest Territories 
4. Kitikmeot, Nunavut 
5. Kivalliq, Nunavut 
6. Northern Qikiqtaaluk, Nunavut 
7. Southern Qikiqtaaluk, Nunavut 
8. Northern British Columbia 
9. Southern British Columbia 
10. Alberta 
11. Saskatchewan 
12. Manitoba 
13. Western Ontario 
14. Eastern Ontario 
15. Northern Quebec 
16. Southern Quebec 
17. Atlantic Canada 

Map of Canada showing the 17 regions for extreme temperature event attribution analysis sub-divided into 89, smaller sections for extreme precipitation event analysis.

Each number below corresponds to the region for extreme event attribution in Canada, with its new sub-divisions.

1. Yukon (4 new sub-divisions)
2. Inuvik, Northwest Territories (5 sub-divisions)
3. Fort Smith, Northwest Territories (7 sub-divisions)
4. Kitikmeot, Nunavut (5 sub-divisions)
5. Kivalliq, Nunavut (5 sub-divisions)
6. Northern Qikiqtaaluk, Nunavut (4 sub-divisions)
7. Southern Qikiqtaaluk, Nunavut (5 sub-divisions)
8. Northern British Columbia (4 sub-divisions)
9. Southern British Columbia (4 sub-divisions)
10. Alberta (6 sub-divisions)
11. Saskatchewan (6 sub-divisions)
12. Manitoba (5 sub-divisions)
13. Western Ontario (5 sub-divisions)
14. Eastern Ontario (4 sub-divisions)
15. Northern Quebec (7 sub-divisions)
16. Southern Quebec (7 sub-divisions)
17. Atlantic Canada (5 sub-divisions)