1.2.1Active indicatorWildfires
1.1Heat and health
1.2Health and extreme weather-related events
1.3Climate suitability for infectious disease transmission
Indicator 1.2.1 · Hazards
Wildfires
Exposure to wildfires and wildfire smoke can have serious health consequences, including burns and other injuries, worsening respiratory and cardiovascular disease, and premature death. Wildfires can also disrupt health services and damage essential infrastructure. This indicator tracks wildfire risk, population exposure to wildfires and wildfire smoke, and mortality associated with PM₂.₅ pollution from wildfire smoke.
Headline finding
In 2016–25, 120 countries (64.2% of those assessed) experienced more days of very high or higher wildfire risk annually on average than in 2006–15. However, the mortality rate associated with PM₂.₅ pollution from wildfire smoke fell by 7.3%.
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Figure 1
Population Exposure to Wildfire
Population exposure to very high or extreme wildfire risk from 2006 to 2025, shown as total exposure in person-days, population-weighted number of days exposed, and change in wildfire exposure over time. Results are available by country, Human Development Index (HDI) group, Lancet Countdown region, or World Health Organization (WHO) region.
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Figure 2
Exposure And Mortality From Wildfire Smoke
Population exposure and mortality associated with wildfire smoke from 2003 to 2025, including population-weighted days above the World Health Organization (WHO) PM2.5 guideline, population-weighted PM2.5 concentrations from fires, population exposure to fire-related PM2.5, deaths attributable to fire-related PM2.5, and deaths per million population. Results are shown globally and by country, Human Development Index (HDI) group, Lancet Countdown region, or WHO region.
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About this indicator
Description
The Fire Danger Risk Indicator is derived from Fire Weather Index (FWI) parameters calculated using ECMWF ERA5 atmospheric reanalysis data. Some very small countries and territories cannot be assigned valid grid cells. Wildfire exposure in person-days is supplied for 210 of the 220 listed countries, while the high-risk-days measure covers all 220 countries. FWI values are classified into six Fire Danger Index (FDI) categories following EFFIS definitions: very low (<5.2), low (5.2–11.2), moderate (11.2–21.3), high (21.3–38.0), very high (38.0–50.0), and extreme (≥50.0). Fire danger exposure is assessed by calculating the average annual number of days classified as very high or extreme fire danger. Changes in exposure are quantified by comparing the most recent decade (2016–2025) against the historical decade (2006–2015). Population-weighted exposure estimates are generated using gridded population data. Wildfire exposure is additionally characterized by using satellite-observed active fire detections.
Authors
Prof Yang Liu, Prof Yun Hang, Dr Dimple Pruthi, Dr Risto Hänninen, Dr Andreas Uppstu, Dr Rostislav Kouznetsov, Evgeny Kadantsev, Prof Mikhail Sofiev
Data downloads
Caveats
The Fire Weather Index reflects meteorological conditions conducive to fire occurrence but does not fully represent real-world wildfire dynamics. Human influences, including land-use change, urban expansion, fire suppression practices, and human-caused ignitions, are not explicitly captured. The index also does not account for the effects of rising atmospheric CO₂ concentrations on vegetation growth and fuel availability, nor for potential climate-driven changes in lightning frequency. Wildfire exposure estimates are subject to additional limitations. Satellite-detected active fire data do not distinguish between wildfires and prescribed or agricultural burns. While the 0.1° spatial resolution enables global coverage and comparability, finer-scale variations in wildfire exposure may not be fully resolved. Local differences in topography, vegetation composition, and socioeconomic factors influencing fire vulnerability and preparedness are also not represented. MODIS and VIIRS retrievals has simmilar omission errors.
This indicator was last updated in September 2026
Data sources
- Fire Weather Index historical data (v4.1) produced by the Copernicus Emergency Management Service for the European Forest Fire Information System (EFFIS).
- Population data from the NASA Socioeconomic Data and Applications Center (SEDAC) Gridded Population of the World (GPWv4).
- MODIS Fire Radiative Power (FRP) observations MOD14/MYD14 from the NASA Fire Information for Resource Management System (FIRMS).
- Cloud cover data from the EarthEnv Global 1-km Cloud dataset.
- VIIRS and MODIS Fire Radiative Power (FRP) observations from the NASA Fire Information for Resource Management System (FIRMS).
- ERA5 global atmospheric reanalysis. Copernicus Climate Change Service (C3S) Climate Data Store (CDS).
- Global classification of land use from the ECOCLIMAP dataset.
- Population data from the NASA Socioeconomic Data and Applications Center (SEDAC) Gridded Population of the World (GPWv4), version 4.11.
- Daily surface concentration of fire-related PM2.5 from the Finnish Meteorological Institute (2026).
- Global mortality data from Global Burden of Disease study (2019).
- FUSION code used to calculate the mortality from annual PM2.5 concentrations.
- Mortality data: Global Health Estimates 2021: Deaths by Cause, Age, Sex, by Country and by Region, 2000-2021. World Health Organization. 2024.