Compare air quality by city

Choose up to three cities and a pollutant to compare modelled concentrations over matching hours.

How to read a comparison

Compare a single pollutant in the same units at a common time. The chart uses UTC so that an hour in one city lines up with the same hour in another. Model resolution can differ between regions and can affect how much local variation the forecast shows.

Open a city page for its nearby station observations, the local timezone and the source of each result.