Cleanest air (lowest PM2.5)
Annual average concentration of fine particulate matter (PM2.5). The WHO guideline is 5 μg/m³ — only a handful of countries meet it.
Headline finding
Iceland leads the world for cleanest air (lowest pm2.5) at 4.0 μg/m³ annual average.
The full top 25: Cleanest air (lowest PM2.5)
Click any country to read its full profile.
- 1 Iceland 4.0
- 2 Bermuda 4.6
- 3 Estonia 4.8
- 4 Puerto Rico 4.9
- 5 Finland 5.0
- 6 Australia 5.3
- 7 New Zealand 5.6
- 8 Grenada 5.6
- 9 Sweden 6.0
- 10 Norway 6.4
- 11 United States 9.1
- 12 Canada 7.7
- 13 Ireland 7.5
- 14 Mauritius 7.0
- 15 United Kingdom 8.0
- 16 Portugal 7.8
- 17 Spain 9.5
- 18 Japan 9.6
- 19 Denmark 7.0
- 20 France 9.5
- 21 Luxembourg 9.0
- 22 Netherlands 9.4
- 23 Switzerland 9.4
- 24 Belgium 10.0
- 25 Germany 10.1
What the numbers show
Iceland's lead at the top of this ranking is -13.0% above the second-place country — a margin tight enough that the top spot has changed hands within the last five years and could change again.
The five countries leading the table — Iceland, Bermuda, Estonia, Puerto Rico, Finland — together set the global benchmark. The next 20 countries fill the rest of the table, with Germany anchoring the list at 10.1.
Figures are drawn from IQAir World Air Quality Report 2024. We use this source because it produces a single, internally consistent dataset rather than aggregating from national statistics offices, which makes year-on-year comparison reliable. The next update is expected when the source publishes its next annual release — see the methodology section below for which year of data is currently shown.
Methodology and caveats
- What this measures
- μg/m³ annual average
- Source
- IQAir World Air Quality Report 2024
- Coverage
- Top 25 countries shown. Full source dataset covers all 195 sovereign states where data is available.
- Refresh cadence
- Updated annually as the source publishes new figures, typically autumn or spring.
- Known caveat
- Country definitions follow the source: where the UN, the World Bank and the CIA Factbook disagree on borders or recognition, we use the figure as published rather than reconciling between bodies. Comparisons across rankings should be made with this in mind.
Frequently asked
Which country tops the ranking for air?
Iceland leads with 4.0 μg/m³ annual average. Bermuda is second at 4.6, with Estonia in third place. Full top-10 with sources is above.
What's the source for the air ranking?
The figures come from IQAir World Air Quality Report 2024. We use this source because it publishes a complete country-by-country dataset using consistent methodology — the alternative of mixing national statistics offices would compromise comparability. Updated annually with the latest available vintage of the data.
How often are the air figures updated?
Once a year, in line with the source institution's publishing schedule. Major institutions like the World Bank, IMF and UNESCO publish annual updates in different months — typically autumn or spring — and the figures here reflect the most recently published vintage. The source footer on the ranking table shows which year's data is currently displayed.