Below is information on the current background air quality in some of Europe's major cities based on data taken from http://www.airqualitynow.eu and recorded at 8:25 am GMT May 17.  City Quality Amsterdam  Very good [16] Berlin  Very good [23] Brussels  N/A Krakow  N/A Oslo  N/A Prague  Very good [16] London  Very good [19] Madrid  Very good [7] Paris  Good [39] Stockholm  Good [43] Zurich  Very good [8] Legend

Below is information on the current background air quality in some of North America's major cities based on data taken from http://www.airnow.gov recorded at 13:05 pm GMT on May 16. 

Below is information on the current background air quality in some of Europe's major cities based on data taken from http://www.airqualitynow.eu and recorded at 8:00 am GMT May 16.  City Quality Amsterdam  Good [33] Berlin  Good [36] Brussels  N/A Krakow  N/A Oslo  Good [27] Prague  Very good [24] London  Very good [19] Madrid  Good [39] Paris  Good [26] Stockholm  Good [31] Zurich  Good [33] Legend

Below is information on the current background air quality in some of Europe's major cities based on data taken from http://www.airqualitynow.eu and recorded at 7:55 am GMT May 14.  City Quality Amsterdam  Very good [21] Berlin  Very good [18] Brussels  N/A Krakow  Moderate [51] Oslo  Very good [16] Prague  Very good [16] London  Very good [20] Madrid  Good [38] Paris  Good [27] Stockholm  Good [25] Zurich  Very good [20] Legend