A clearer
view of
your city.
Compare air quality and outdoor thermal stress in 93,028 cities and towns worldwide.
Illustrative cityscape93,028 places · One shared method · Free to explore
The same measures.
A world of places.
Start with a city. See its global position, then compare the conditions behind the score.
Latest environmental windowSeptember 2026
Published8 Oct, 13:45 BST
Automatic source checksSetup pendingNo verified source-check time
Complete monthly observations. Source checks are dated snapshots; Mac health is not monitored live.
Explore the rankings
September 2026 · Higher scores mean lower exposure.
Verified environmental edition · September 2026
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GLOBAL RANKPLACESCOREAIR QUALITYTHERMAL STRESSCOMPARE
Higher score = cleaner background air and fewer heat/cold stress hours. Shared scores share a rank.
What goes into a score?
Population-weighted background conditions, compared with one shared method across borders.
Air quality
PM2.5 + surface ozone. Lower pollution receives a higher relative score.
Thermal stress
Hours of strong heat + cold exposure. Fewer stress hours receive a higher score.
The balanced score gives each pillar 50%. Scores use five-point bands and shared global ranks. Nearby places may share a background grid cell.
See how the ranking works See your city in a wider world.
Start with a place you know.