Air quality matters for travel

French Polynesia, Puerto Rico, U.S. Virgin Islands, Barbados, New Caledonia, Iceland, Bermuda, Réunion, Andorra, Australia, Grenada, Panama and Estonia are the jurisdictions IQAir identifies as having annual PM2.5 concentrations within the WHO reference level in its 2025 World Air Quality Report. (iqair.com) IQAir’s 2025 analysis drew on monitoring stations across 9,446 cities in 143 countries, added 12 countries to this year’s dataset and found 54 countries recorded rising annual PM2.5 while 75 saw declines. (iqair.com) The five countries with the highest national annual averages in 2025 were Pakistan (67.3 µg/m³), Bangladesh (66.1 µg/m³), Tajikistan (57.3 µg/m³), Chad (53.6 µg/m³) and the Democratic Republic of the Congo (50.2 µg/m³). (iqair.com) Loni, India recorded the world’s highest city-level annual PM2.5 in 2025 at 112.5 µg/m³ — roughly 23% higher than in 2024 and more than 22 times the WHO annual reference — while Nieuwoudtville, South Africa was the cleanest city with an annual average of 1.0 µg/m³. (iqair.com) The World Health Organization’s 2021 Global Air Quality Guidelines recommend an annual PM2.5 limit of 5 µg/m³, a benchmark IQAir used to assess cities and countries and which 130 of the 143 countries covered in the 2025 report exceeded. (who.int; iqair.com) Europe’s results were mixed in 2025: Andorra, Estonia and Iceland met the WHO annual PM2.5 reference while several other European countries recorded seasonal spikes linked to winter wood burning, Canadian wildfire smoke and Saharan dust carried into the region. (iqair.com)