Wildfire & fire weather

Explore climate indicators and data resources relevant to wildfire and fire weather in Canada.

Module

Climate Hazards

Format

Article

Time to completion

15 minutes

Last update: August 2026

NOTE: The information on this page is neither prescriptive nor exhaustive. Content is updated periodically as more information becomes accessible. Readers are encouraged to consider complementary information.

Key message(s) from Canada’s Changing Climate Report 2026

Key Message 8.11:The fire season has lengthened in most parts of Canada (high confidence) and is projected to continue to lengthen as the global average temperature increases (high confidence). Fire weather—characterized by hot, dry, and windy conditions conducive to wildfires—has increased in Alberta and British Columbia (medium confidence), with some indications of increases in other regions (very low confidence). The frequency and intensity of extreme fire weather conditions are projected to increase in most regions of Canada as global average temperature rises (high confidence).

Future changes in wildfire and fire weather in Canada

Wildfire and fire weather are compound hazards, meaning that multiple climate conditions contribute to their occurrence. To better understand wildfire and fire weather, this table can be considered with the tables on Extreme heat and heatwaves and Drought.

This table connects a climate-related hazard with readily available and relevant climate variables and indicators. Knowledge of regional characteristics is key for interpreting and using climate information in local planning. Where possible, project context, local knowledge, traditional knowledge, and/or additional assessments or studies can inform indicator selection and interpretation, to support the link from data to decision-making. Visit the Climate Hazards module to see the full list of hazard tables available, and to view the methodology and inclusion criteria for the tables.

Future changes	Relevant climate variables and indicators	Climate Data Sources*
Increasing frequency and severity of fire weather conditions, and longer fire seasons.	Canadian Forest Fire Weather Index Weather Information (FWI) System metrics: Buildup Index (BUI): A unitless metric that describes the forest floor drought conditions, with larger values indicating an increased fire danger. BUI is calculated using temperature, relative humidity, and precipitation. Extreme BUI: The 95th percentile of daily BUI across the May–September central fire season. This is a measure of severity of high fire weather conditions. Count of days with BUI>60: Number of days each year that the BUI exceeds a threshold of 60. This is a measure of frequency of high fire weather conditions. Other Fire Weather Index System components: Similar metrics are available for other components of the FWI System, including the fuel moisture codes (Fine Fuel Moisture Code, Duff Moisture Code, and Drought Code) and fire behaviour indicators (Initial Spread Index, Fire Weather Index). Fire season length (FSL): The number of days in the wildfire season, when fires are most likely to start and spread. It is commonly defined based on maximum daily temperature.	National ClimateData.ca (Extreme BUI, Count of days with BUI>60, Buildup, Buildup Index, Fire season length, Other Fire Weather Index System metrics) Canadian Wildland Fire Information System (Seasonal forecasts of fire severity anomaly, fire severity rating) Forest Change Data Catalogue (fire season lenght)
Higher number of large fires in some zones.	Number of large wildland fires: Annual number of fires greater than 200 hectares (ha) that occur per 100,000 ha and was calculated per Homogeneous Fire Regime (HFR) zones.	National Forest Change Data Catalogue (Number of large wildland fires)
Larger area burned by wildfires.	Wildfire-burned area: Area burned by fires.	National Forest Change Data Catalogue (Annual area burned)

Future changes

Relevant climate variables and indicators

Climate Data Sources*

Increasing frequency and severity of fire weather conditions, and longer fire seasons.

Canadian Forest Fire Weather Index Weather Information (FWI) System metrics:

Buildup Index (BUI): A unitless metric that describes the forest floor drought conditions, with larger values indicating an increased fire danger. BUI is calculated using temperature, relative humidity, and precipitation.
- Extreme BUI: The 95th percentile of daily BUI across the May–September central fire season. This is a measure of severity of high fire weather conditions.
- Count of days with BUI>60: Number of days each year that the BUI exceeds a threshold of 60. This is a measure of frequency of high fire weather conditions.
Other Fire Weather Index System components: Similar metrics are available for other components of the FWI System, including the fuel moisture codes (Fine Fuel Moisture Code, Duff Moisture Code, and Drought Code) and fire behaviour indicators (Initial Spread Index, Fire Weather Index).
Fire season length (FSL): The number of days in the wildfire season, when fires are most likely to start and spread. It is commonly defined based on maximum daily temperature.

National

ClimateData.ca (Extreme BUI, Count of days with BUI>60, Buildup, Buildup Index, Fire season length, Other Fire Weather Index System metrics)
Canadian Wildland Fire Information System (Seasonal forecasts of fire severity anomaly, fire severity rating)
Forest Change Data Catalogue (fire season lenght)

Higher number of large fires in some zones.

Number of large wildland fires: Annual number of fires greater than 200 hectares (ha) that occur per 100,000 ha and was calculated per Homogeneous Fire Regime (HFR) zones.

National

Forest Change Data Catalogue (Number of large wildland fires)

Larger area burned by wildfires.

Wildfire-burned area: Area burned by fires.

National

Forest Change Data Catalogue (Annual area burned)

* Additional advanced data analytics tools listed on the Climate Hazards page provide more complex data download options, programming environments and specialized software to support bulk downloads, custom data processing, and analysis of large Canada-wide datasets, and include additional data not listed here.