Extreme fire-smoke exposure days rise from 16 to 66 per year globally since the 1990s
Extreme fire-PM2.5 exposure events have tripled globally since the 1990s, while wildfire and other fire activity contributed to above-average particulate pollution across several regions in 2025, according to the World Meteorological Organization’s latest Air Quality and Climate Bulletin. The September 7, 2026 assessment places that trend alongside declines in other sources of PM2.5 in parts of Europe and North America.


