SmogRank / Episodes / United Kingdom
United Kingdom and Belgium, September 2023
For 4 days, from 7 to 10 September 2023, 42 cities in the United Kingdom, Belgium, France and 1 more countries had PM2.5 at least twice their usual for the time of year. The worst reading was Canvey Island, England, United Kingdom: 53.0 µg/m³ on 10 September, about 11× its usual 4.9.
No cause named We have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached 42 in 4 countries
Days 4 7 to 10 September 2023
Worst day 9 September 29 cities counted
Furthest above usual 11× Canvey Island
Day by day
Play 9 September 29 cities at twice their usual or more
Biggleswade Royal Leamington Spa Oxford Hayes Chesterfield Reading Newmarket Sheffield Barnsley Kingston upon Hull Andover York Southampton Portsmouth Brighton Seaford Irlam Warrington Bristol Middlesbrough Wigan Newport Cardiff Briton Ferry Newton Abbot Barnstaple Lille Kortrijk Douai Tournai Denain Valenciennes 's-Gravenzande Maassluis The Hague Mons Stabroek Rotterdam Hillegom Ridderkerk Velsen-Zuid Velserbroek Badhoevedorp Zaanstad Charleroi Breda Amsterdam Purmerend Maarssen IJsselstein Medemblik Utrecht Tilburg Mol Andenne Eindhoven Barneveld Flémalle-Haute Marche-en-Famenne Liège Nijmegen Venray Waregem Izegem Grays Roubaix Menen Leeds Gent Preston Birmingham Manchester Kapellen Lochristi Liverpool Belfast Speke Canterbury Brussels Dublin Nottingham London Banbridge Stoke-on-Trent Plymouth Grimbergen Evergem Maldegem Norwich Willebroek Dún Laoghaire Roeselare Aarschot Koksijde Saltash Beveren Dagenham Dartford Antwerp Bexley Zwijndrecht Clacton-on-Sea Dunkirk Canvey Island 4 Sep 5 6 7 8 9 10 11 12 13 Every measured city in the area, coloured by its PM2.5 that day; a dark ring marks a city at twice its usual or more. Bars: cities counted each day, coloured by their median level. Choose a day or press play; without JavaScript, the days link to that day's world ranking.
How it spread
Dunkirk Dunkirk, 4 September: 15.9 µg/m³, 2.9× usual Dunkirk, 5 September: 12.8 µg/m³, 2.3× usual Dunkirk, 6 September: 28.0 µg/m³, 5.1× usual Dunkirk, 7 September: 27.3 µg/m³, 5.0× usual Dunkirk, 8 September: 29.9 µg/m³, 5.4× usual Dunkirk, 9 September: 48.5 µg/m³, 8.8× usual Dunkirk, 10 September: 27.2 µg/m³, 4.9× usual Dunkirk, 11 September: 13.9 µg/m³, 2.5× usual Dunkirk, 12 September: 12.3 µg/m³, 2.2× usual Dunkirk, 13 September: 6.5 µg/m³, 1.2× usual Canvey Island Canvey Island, 4 September: no reading Canvey Island, 5 September: 21.5 µg/m³, 4.3× usual Canvey Island, 6 September: 27.3 µg/m³, 5.5× usual Canvey Island, 7 September: 36.1 µg/m³, 7.2× usual Canvey Island, 8 September: 38.7 µg/m³, 7.7× usual Canvey Island, 9 September: 23.5 µg/m³, 4.7× usual Canvey Island, 10 September: 53.0 µg/m³, 11× usual Canvey Island, 11 September: 22.7 µg/m³, 4.5× usual Canvey Island, 12 September: 8.1 µg/m³, 1.6× usual Canvey Island, 13 September: 4.6 µg/m³, 0.9× usual Dartford Dartford, 4 September: no reading Dartford, 5 September: no reading Dartford, 6 September: no reading Dartford, 7 September: 38.3 µg/m³, 7.2× usual Dartford, 8 September: 13.6 µg/m³, 2.6× usual Dartford, 9 September: 15.9 µg/m³, 3.0× usual Dartford, 10 September: 39.2 µg/m³, 7.4× usual Dartford, 11 September: 10.7 µg/m³, 2.0× usual Dartford, 12 September: 6.5 µg/m³, 1.2× usual Dartford, 13 September: 6.5 µg/m³, 1.2× usual Bexley Bexley, 4 September: 23.0 µg/m³, 4.6× usual Bexley, 5 September: 18.2 µg/m³, 3.6× usual Bexley, 6 September: 20.6 µg/m³, 4.1× usual Bexley, 7 September: 33.4 µg/m³, 6.7× usual Bexley, 8 September: 25.9 µg/m³, 5.2× usual Bexley, 9 September: 16.3 µg/m³, 3.3× usual Bexley, 10 September: 38.9 µg/m³, 7.8× usual Bexley, 11 September: 18.7 µg/m³, 3.7× usual Bexley, 12 September: 6.5 µg/m³, 1.3× usual Bexley, 13 September: 4.1 µg/m³, 0.8× usual Dagenham Dagenham, 4 September: 15.8 µg/m³, 3.2× usual Dagenham, 5 September: 15.9 µg/m³, 3.2× usual Dagenham, 6 September: 22.1 µg/m³, 4.4× usual Dagenham, 7 September: 32.7 µg/m³, 6.5× usual Dagenham, 8 September: 29.5 µg/m³, 5.9× usual Dagenham, 9 September: no reading Dagenham, 10 September: 36.6 µg/m³, 7.3× usual Dagenham, 11 September: 11.1 µg/m³, 2.2× usual Dagenham, 12 September: 5.6 µg/m³, 1.1× usual Dagenham, 13 September: 2.8 µg/m³, 0.6× usual Grays Grays, 4 September: 15.3 µg/m³, 2.0× usual Grays, 5 September: 18.0 µg/m³, 2.4× usual Grays, 6 September: 24.8 µg/m³, 3.3× usual Grays, 7 September: 32.5 µg/m³, 4.3× usual Grays, 8 September: 20.3 µg/m³, 2.7× usual Grays, 9 September: no reading Grays, 10 September: 32.5 µg/m³, 4.3× usual Grays, 11 September: 9.5 µg/m³, 1.3× usual Grays, 12 September: 5.6 µg/m³, 0.7× usual Grays, 13 September: 5.3 µg/m³, 0.7× usual Clacton-on-Sea Clacton-on-Sea, 4 September: no reading Clacton-on-Sea, 5 September: 15.0 µg/m³, 3.0× usual Clacton-on-Sea, 6 September: 17.1 µg/m³, 3.4× usual Clacton-on-Sea, 7 September: 31.6 µg/m³, 6.3× usual Clacton-on-Sea, 8 September: 41.8 µg/m³, 8.4× usual Clacton-on-Sea, 9 September: 28.9 µg/m³, 5.8× usual Clacton-on-Sea, 10 September: 35.7 µg/m³, 7.1× usual Clacton-on-Sea, 11 September: 19.6 µg/m³, 3.9× usual Clacton-on-Sea, 12 September: 7.1 µg/m³, 1.4× usual Clacton-on-Sea, 13 September: 5.0 µg/m³, 1.0× usual London London, 4 September: 18.1 µg/m³, 3.0× usual London, 5 September: 17.3 µg/m³, 2.8× usual London, 6 September: 20.5 µg/m³, 3.4× usual London, 7 September: 30.5 µg/m³, 5.0× usual London, 8 September: 19.4 µg/m³, 3.2× usual London, 9 September: 20.7 µg/m³, 3.4× usual London, 10 September: 33.6 µg/m³, 5.5× usual London, 11 September: 10.2 µg/m³, 1.7× usual London, 12 September: 6.0 µg/m³, 1.0× usual London, 13 September: 5.1 µg/m³, 0.8× usual Canterbury Canterbury, 4 September: no reading Canterbury, 5 September: 15.6 µg/m³, 3.0× usual Canterbury, 6 September: 17.8 µg/m³, 3.4× usual Canterbury, 7 September: 26.5 µg/m³, 5.1× usual Canterbury, 8 September: 20.5 µg/m³, 3.9× usual Canterbury, 9 September: 16.8 µg/m³, 3.2× usual Canterbury, 10 September: 27.8 µg/m³, 5.3× usual Canterbury, 11 September: 15.8 µg/m³, 3.0× usual Canterbury, 12 September: 8.1 µg/m³, 1.6× usual Canterbury, 13 September: 5.0 µg/m³, 1.0× usual Koksijde Koksijde, 4 September: 13.0 µg/m³, 2.6× usual Koksijde, 5 September: 12.8 µg/m³, 2.6× usual Koksijde, 6 September: 17.5 µg/m³, 3.5× usual Koksijde, 7 September: 25.0 µg/m³, 5.0× usual Koksijde, 8 September: 26.6 µg/m³, 5.3× usual Koksijde, 9 September: 35.0 µg/m³, 7.0× usual Koksijde, 10 September: 23.0 µg/m³, 4.6× usual Koksijde, 11 September: 12.6 µg/m³, 2.5× usual Koksijde, 12 September: 11.1 µg/m³, 2.2× usual Koksijde, 13 September: 5.5 µg/m³, 1.1× usual Plymouth Plymouth, 4 September: no reading Plymouth, 5 September: 8.6 µg/m³, 1.3× usual Plymouth, 6 September: 14.5 µg/m³, 2.3× usual Plymouth, 7 September: 16.5 µg/m³, 2.6× usual Plymouth, 8 September: 36.7 µg/m³, 5.7× usual Plymouth, 9 September: 21.1 µg/m³, 3.3× usual Plymouth, 10 September: 14.6 µg/m³, 2.3× usual Plymouth, 11 September: 9.6 µg/m³, 1.5× usual Plymouth, 12 September: 5.1 µg/m³, 0.8× usual Plymouth, 13 September: 4.2 µg/m³, 0.7× usual Saltash Saltash, 4 September: no reading Saltash, 5 September: 7.8 µg/m³, 1.6× usual Saltash, 6 September: 14.7 µg/m³, 2.9× usual Saltash, 7 September: 17.2 µg/m³, 3.4× usual Saltash, 8 September: 36.2 µg/m³, 7.2× usual Saltash, 9 September: 19.4 µg/m³, 3.9× usual Saltash, 10 September: 12.4 µg/m³, 2.5× usual Saltash, 11 September: 9.5 µg/m³, 1.9× usual Saltash, 12 September: 5.6 µg/m³, 1.1× usual Saltash, 13 September: 3.1 µg/m³, 0.6× usual Nottingham Nottingham, 4 September: no reading Nottingham, 5 September: 14.7 µg/m³, 2.4× usual Nottingham, 6 September: 21.4 µg/m³, 3.6× usual Nottingham, 7 September: 21.0 µg/m³, 3.5× usual Nottingham, 8 September: 32.2 µg/m³, 5.4× usual Nottingham, 9 September: 33.0 µg/m³, 5.5× usual Nottingham, 10 September: 22.7 µg/m³, 3.8× usual Nottingham, 11 September: 16.0 µg/m³, 2.7× usual Nottingham, 12 September: 6.1 µg/m³, 1.0× usual Nottingham, 13 September: 4.1 µg/m³, 0.7× usual Dún Laoghaire Dún Laoghaire, 4 September: 5.8 µg/m³, 1.2× usual Dún Laoghaire, 5 September: 15.6 µg/m³, 3.1× usual Dún Laoghaire, 6 September: 11.1 µg/m³, 2.2× usual Dún Laoghaire, 7 September: 13.8 µg/m³, 2.8× usual Dún Laoghaire, 8 September: 31.5 µg/m³, 6.3× usual Dún Laoghaire, 9 September: 10.6 µg/m³, 2.1× usual Dún Laoghaire, 10 September: 15.1 µg/m³, 3.0× usual Dún Laoghaire, 11 September: 3.8 µg/m³, 0.8× usual Dún Laoghaire, 12 September: 3.4 µg/m³, 0.7× usual Dún Laoghaire, 13 September: 4.6 µg/m³, 0.9× usual Speke Speke, 4 September: no reading Speke, 5 September: 17.7 µg/m³, 3.1× usual Speke, 6 September: 15.6 µg/m³, 2.7× usual Speke, 7 September: 22.0 µg/m³, 3.8× usual Speke, 8 September: 29.8 µg/m³, 5.1× usual Speke, 9 September: 30.6 µg/m³, 5.3× usual Speke, 10 September: no reading Speke, 11 September: no reading Speke, 12 September: no reading Speke, 13 September: no reading Banbridge Banbridge, 4 September: 6.0 µg/m³, 1.2× usual Banbridge, 5 September: 11.2 µg/m³, 2.2× usual Banbridge, 6 September: 10.6 µg/m³, 2.1× usual Banbridge, 7 September: 13.3 µg/m³, 2.7× usual Banbridge, 8 September: 28.1 µg/m³, 5.6× usual Banbridge, 9 September: 10.5 µg/m³, 2.1× usual Banbridge, 10 September: 14.0 µg/m³, 2.8× usual Banbridge, 11 September: 3.5 µg/m³, 0.7× usual Banbridge, 12 September: 3.1 µg/m³, 0.6× usual Banbridge, 13 September: 6.1 µg/m³, 1.2× usual Dublin Dublin, 4 September: 6.0 µg/m³, 1.2× usual Dublin, 5 September: 11.6 µg/m³, 2.3× usual Dublin, 6 September: 10.2 µg/m³, 2.0× usual Dublin, 7 September: 13.2 µg/m³, 2.6× usual Dublin, 8 September: 27.2 µg/m³, 5.4× usual Dublin, 9 September: 10.0 µg/m³, 2.0× usual Dublin, 10 September: 14.5 µg/m³, 2.9× usual Dublin, 11 September: 3.4 µg/m³, 0.7× usual Dublin, 12 September: 3.1 µg/m³, 0.6× usual Dublin, 13 September: 5.5 µg/m³, 1.1× usual Belfast Belfast, 4 September: no reading Belfast, 5 September: 10.6 µg/m³, 2.1× usual Belfast, 6 September: 10.6 µg/m³, 2.1× usual Belfast, 7 September: 13.4 µg/m³, 2.7× usual Belfast, 8 September: 26.4 µg/m³, 5.3× usual Belfast, 9 September: 23.4 µg/m³, 4.7× usual Belfast, 10 September: 7.0 µg/m³, 1.4× usual Belfast, 11 September: 7.2 µg/m³, 1.4× usual Belfast, 12 September: 3.1 µg/m³, 0.6× usual Belfast, 13 September: 4.9 µg/m³, 1.0× usual Zwijndrecht Zwijndrecht, 4 September: 11.0 µg/m³, 2.1× usual Zwijndrecht, 5 September: 7.9 µg/m³, 1.5× usual Zwijndrecht, 6 September: 8.0 µg/m³, 1.5× usual Zwijndrecht, 7 September: 11.1 µg/m³, 2.1× usual Zwijndrecht, 8 September: 21.6 µg/m³, 4.2× usual Zwijndrecht, 9 September: 43.8 µg/m³, 8.4× usual Zwijndrecht, 10 September: 18.7 µg/m³, 3.6× usual Zwijndrecht, 11 September: 15.9 µg/m³, 3.1× usual Zwijndrecht, 12 September: 26.2 µg/m³, 5.0× usual Zwijndrecht, 13 September: 9.9 µg/m³, 1.9× usual Antwerp Antwerp, 4 September: 9.8 µg/m³, 1.9× usual Antwerp, 5 September: 7.2 µg/m³, 1.4× usual Antwerp, 6 September: 7.0 µg/m³, 1.3× usual Antwerp, 7 September: 10.9 µg/m³, 2.1× usual Antwerp, 8 September: 19.2 µg/m³, 3.7× usual Antwerp, 9 September: 40.5 µg/m³, 7.8× usual Antwerp, 10 September: 18.7 µg/m³, 3.6× usual Antwerp, 11 September: 15.3 µg/m³, 2.9× usual Antwerp, 12 September: 24.2 µg/m³, 4.7× usual Antwerp, 13 September: 10.7 µg/m³, 2.1× usual Beveren Beveren, 4 September: 10.5 µg/m³, 2.1× usual Beveren, 5 September: no reading Beveren, 6 September: 8.1 µg/m³, 1.6× usual Beveren, 7 September: 11.0 µg/m³, 2.2× usual Beveren, 8 September: 21.2 µg/m³, 4.2× usual Beveren, 9 September: 36.3 µg/m³, 7.3× usual Beveren, 10 September: 18.6 µg/m³, 3.7× usual Beveren, 11 September: 16.5 µg/m³, 3.3× usual Beveren, 12 September: 24.1 µg/m³, 4.8× usual Beveren, 13 September: 9.6 µg/m³, 1.9× usual Roeselare Roeselare, 4 September: 13.3 µg/m³, 2.5× usual Roeselare, 5 September: 12.5 µg/m³, 2.4× usual Roeselare, 6 September: 11.0 µg/m³, 2.1× usual Roeselare, 7 September: 18.8 µg/m³, 3.5× usual Roeselare, 8 September: 22.6 µg/m³, 4.3× usual Roeselare, 9 September: 35.2 µg/m³, 6.6× usual Roeselare, 10 September: 16.6 µg/m³, 3.1× usual Roeselare, 11 September: 17.0 µg/m³, 3.2× usual Roeselare, 12 September: 18.2 µg/m³, 3.4× usual Roeselare, 13 September: 6.7 µg/m³, 1.3× usual Aarschot Aarschot, 4 September: 9.6 µg/m³, 1.9× usual Aarschot, 5 September: 5.9 µg/m³, 1.2× usual Aarschot, 6 September: 6.0 µg/m³, 1.2× usual Aarschot, 7 September: 10.5 µg/m³, 2.1× usual Aarschot, 8 September: 13.8 µg/m³, 2.8× usual Aarschot, 9 September: 35.0 µg/m³, 7.0× usual Aarschot, 10 September: 14.4 µg/m³, 2.9× usual Aarschot, 11 September: 11.8 µg/m³, 2.4× usual Aarschot, 12 September: 14.2 µg/m³, 2.8× usual Aarschot, 13 September: 10.0 µg/m³, 2.0× usual Evergem Evergem, 4 September: 12.8 µg/m³, 2.2× usual Evergem, 5 September: 11.8 µg/m³, 2.1× usual Evergem, 6 September: 11.3 µg/m³, 2.0× usual Evergem, 7 September: 15.9 µg/m³, 2.8× usual Evergem, 8 September: 20.4 µg/m³, 3.6× usual Evergem, 9 September: 33.5 µg/m³, 5.9× usual Evergem, 10 September: 20.6 µg/m³, 3.6× usual Evergem, 11 September: 16.8 µg/m³, 2.9× usual Evergem, 12 September: 22.7 µg/m³, 4.0× usual Evergem, 13 September: 9.1 µg/m³, 1.6× usual Maldegem Maldegem, 4 September: 13.8 µg/m³, 2.6× usual Maldegem, 5 September: 12.4 µg/m³, 2.3× usual Maldegem, 6 September: 12.1 µg/m³, 2.3× usual Maldegem, 7 September: 18.0 µg/m³, 3.4× usual Maldegem, 8 September: 24.1 µg/m³, 4.5× usual Maldegem, 9 September: 31.6 µg/m³, 6.0× usual Maldegem, 10 September: 20.1 µg/m³, 3.8× usual Maldegem, 11 September: 19.0 µg/m³, 3.6× usual Maldegem, 12 September: 20.5 µg/m³, 3.9× usual Maldegem, 13 September: 6.4 µg/m³, 1.2× usual Willebroek Willebroek, 4 September: 9.2 µg/m³, 1.8× usual Willebroek, 5 September: 5.6 µg/m³, 1.1× usual Willebroek, 6 September: 5.9 µg/m³, 1.2× usual Willebroek, 7 September: 9.7 µg/m³, 1.9× usual Willebroek, 8 September: 15.4 µg/m³, 3.1× usual Willebroek, 9 September: 31.5 µg/m³, 6.3× usual Willebroek, 10 September: 14.6 µg/m³, 2.9× usual Willebroek, 11 September: 12.8 µg/m³, 2.6× usual Willebroek, 12 September: 20.9 µg/m³, 4.2× usual Willebroek, 13 September: 9.6 µg/m³, 1.9× usual Lochristi Lochristi, 4 September: 9.4 µg/m³, 1.6× usual Lochristi, 5 September: 7.8 µg/m³, 1.3× usual Lochristi, 6 September: 7.4 µg/m³, 1.3× usual Lochristi, 7 September: 11.8 µg/m³, 2.0× usual Lochristi, 8 September: 17.7 µg/m³, 3.0× usual Lochristi, 9 September: 31.0 µg/m³, 5.3× usual Lochristi, 10 September: 16.2 µg/m³, 2.7× usual Lochristi, 11 September: 15.4 µg/m³, 2.6× usual Lochristi, 12 September: 22.2 µg/m³, 3.8× usual Lochristi, 13 September: 7.8 µg/m³, 1.3× usual Izegem Izegem, 4 September: 11.8 µg/m³, 1.6× usual Izegem, 5 September: 12.2 µg/m³, 1.6× usual Izegem, 6 September: 10.6 µg/m³, 1.4× usual Izegem, 7 September: 16.0 µg/m³, 2.2× usual Izegem, 8 September: 20.2 µg/m³, 2.7× usual Izegem, 9 September: 30.5 µg/m³, 4.1× usual Izegem, 10 September: 15.4 µg/m³, 2.1× usual Izegem, 11 September: 17.1 µg/m³, 2.3× usual Izegem, 12 September: 21.3 µg/m³, 2.9× usual Izegem, 13 September: 7.4 µg/m³, 1.0× usual Norwich Norwich, 4 September: no reading Norwich, 5 September: 12.3 µg/m³, 2.5× usual Norwich, 6 September: no reading Norwich, 7 September: no reading Norwich, 8 September: 23.7 µg/m³, 4.7× usual Norwich, 9 September: 30.1 µg/m³, 6.0× usual Norwich, 10 September: 23.0 µg/m³, 4.6× usual Norwich, 11 September: 17.8 µg/m³, 3.6× usual Norwich, 12 September: 6.9 µg/m³, 1.4× usual Norwich, 13 September: 4.1 µg/m³, 0.8× usual Manchester Manchester, 4 September: no reading Manchester, 5 September: 11.9 µg/m³, 2.1× usual Manchester, 6 September: 13.0 µg/m³, 2.3× usual Manchester, 7 September: 18.9 µg/m³, 3.4× usual Manchester, 8 September: 22.9 µg/m³, 4.1× usual Manchester, 9 September: 29.3 µg/m³, 5.2× usual Manchester, 10 September: 17.0 µg/m³, 3.0× usual Manchester, 11 September: 14.9 µg/m³, 2.7× usual Manchester, 12 September: 5.1 µg/m³, 0.9× usual Manchester, 13 September: 4.6 µg/m³, 0.8× usual Grimbergen Grimbergen, 4 September: 8.7 µg/m³, 1.7× usual Grimbergen, 5 September: 5.9 µg/m³, 1.2× usual Grimbergen, 6 September: 5.8 µg/m³, 1.2× usual Grimbergen, 7 September: 9.6 µg/m³, 1.9× usual Grimbergen, 8 September: 15.1 µg/m³, 3.0× usual Grimbergen, 9 September: 29.1 µg/m³, 5.8× usual Grimbergen, 10 September: 14.0 µg/m³, 2.8× usual Grimbergen, 11 September: 12.6 µg/m³, 2.5× usual Grimbergen, 12 September: 16.2 µg/m³, 3.2× usual Grimbergen, 13 September: 9.9 µg/m³, 2.0× usual Stoke-on-Trent Stoke-on-Trent, 4 September: no reading Stoke-on-Trent, 5 September: 11.3 µg/m³, 2.3× usual Stoke-on-Trent, 6 September: 13.7 µg/m³, 2.7× usual Stoke-on-Trent, 7 September: 15.0 µg/m³, 3.0× usual Stoke-on-Trent, 8 September: 21.6 µg/m³, 4.3× usual Stoke-on-Trent, 9 September: 28.7 µg/m³, 5.7× usual Stoke-on-Trent, 10 September: 17.8 µg/m³, 3.6× usual Stoke-on-Trent, 11 September: 15.3 µg/m³, 3.1× usual Stoke-on-Trent, 12 September: 5.2 µg/m³, 1.0× usual Stoke-on-Trent, 13 September: no reading Leeds Leeds, 4 September: no reading Leeds, 5 September: 15.5 µg/m³, 2.7× usual Leeds, 6 September: 16.8 µg/m³, 2.9× usual Leeds, 7 September: 24.5 µg/m³, 4.2× usual Leeds, 8 September: 21.4 µg/m³, 3.7× usual Leeds, 9 September: 28.3 µg/m³, 4.9× usual Leeds, 10 September: 15.2 µg/m³, 2.6× usual Leeds, 11 September: 16.3 µg/m³, 2.8× usual Leeds, 12 September: 5.1 µg/m³, 0.9× usual Leeds, 13 September: 4.5 µg/m³, 0.8× usual Brussels Brussels, 4 September: 12.1 µg/m³, 2.4× usual Brussels, 5 September: 9.2 µg/m³, 1.8× usual Brussels, 6 September: 9.1 µg/m³, 1.8× usual Brussels, 7 September: 10.9 µg/m³, 2.2× usual Brussels, 8 September: 15.8 µg/m³, 3.2× usual Brussels, 9 September: 26.9 µg/m³, 5.4× usual Brussels, 10 September: 12.5 µg/m³, 2.5× usual Brussels, 11 September: 11.5 µg/m³, 2.3× usual Brussels, 12 September: 14.5 µg/m³, 2.9× usual Brussels, 13 September: 4.6 µg/m³, 0.9× usual Roubaix Roubaix, 4 September: 12.1 µg/m³, 2.0× usual Roubaix, 5 September: 14.0 µg/m³, 2.3× usual Roubaix, 6 September: 14.7 µg/m³, 2.4× usual Roubaix, 7 September: 17.4 µg/m³, 2.9× usual Roubaix, 8 September: 19.7 µg/m³, 3.2× usual Roubaix, 9 September: 26.8 µg/m³, 4.4× usual Roubaix, 10 September: 14.0 µg/m³, 2.3× usual Roubaix, 11 September: no reading Roubaix, 12 September: no reading Roubaix, 13 September: 7.5 µg/m³, 1.2× usual Kapellen Kapellen, 4 September: 9.0 µg/m³, 1.8× usual Kapellen, 5 September: 6.8 µg/m³, 1.4× usual Kapellen, 6 September: 6.5 µg/m³, 1.3× usual Kapellen, 7 September: 9.6 µg/m³, 1.9× usual Kapellen, 8 September: 20.1 µg/m³, 4.0× usual Kapellen, 9 September: 26.7 µg/m³, 5.3× usual Kapellen, 10 September: 17.9 µg/m³, 3.6× usual Kapellen, 11 September: 14.5 µg/m³, 2.9× usual Kapellen, 12 September: 23.2 µg/m³, 4.6× usual Kapellen, 13 September: 8.4 µg/m³, 1.7× usual Liverpool Liverpool, 4 September: no reading Liverpool, 5 September: 11.8 µg/m³, 2.4× usual Liverpool, 6 September: 10.7 µg/m³, 2.1× usual Liverpool, 7 September: 16.3 µg/m³, 3.3× usual Liverpool, 8 September: 24.0 µg/m³, 4.8× usual Liverpool, 9 September: 26.5 µg/m³, 5.3× usual Liverpool, 10 September: 20.0 µg/m³, 4.0× usual Liverpool, 11 September: 12.4 µg/m³, 2.5× usual Liverpool, 12 September: 2.8 µg/m³, 0.6× usual Liverpool, 13 September: 3.0 µg/m³, 0.6× usual Birmingham Birmingham, 4 September: no reading Birmingham, 5 September: 12.2 µg/m³, 2.4× usual Birmingham, 6 September: 13.7 µg/m³, 2.7× usual Birmingham, 7 September: 16.2 µg/m³, 3.2× usual Birmingham, 8 September: 20.5 µg/m³, 4.0× usual Birmingham, 9 September: 25.8 µg/m³, 5.1× usual Birmingham, 10 September: 23.2 µg/m³, 4.5× usual Birmingham, 11 September: 14.8 µg/m³, 2.9× usual Birmingham, 12 September: 4.9 µg/m³, 1.0× usual Birmingham, 13 September: 4.3 µg/m³, 0.8× usual Gent Gent, 4 September: 9.4 µg/m³, 1.8× usual Gent, 5 September: 7.8 µg/m³, 1.5× usual Gent, 6 September: 7.9 µg/m³, 1.5× usual Gent, 7 September: 11.5 µg/m³, 2.3× usual Gent, 8 September: 14.4 µg/m³, 2.8× usual Gent, 9 September: 25.7 µg/m³, 5.0× usual Gent, 10 September: 14.6 µg/m³, 2.9× usual Gent, 11 September: 13.1 µg/m³, 2.6× usual Gent, 12 September: 17.7 µg/m³, 3.5× usual Gent, 13 September: 8.0 µg/m³, 1.6× usual Preston Preston, 4 September: no reading Preston, 5 September: 10.3 µg/m³, 2.1× usual Preston, 6 September: 10.0 µg/m³, 2.0× usual Preston, 7 September: 19.0 µg/m³, 3.8× usual Preston, 8 September: 20.2 µg/m³, 4.0× usual Preston, 9 September: 25.1 µg/m³, 5.0× usual Preston, 10 September: 15.5 µg/m³, 3.1× usual Preston, 11 September: 10.6 µg/m³, 2.1× usual Preston, 12 September: 3.7 µg/m³, 0.7× usual Preston, 13 September: 3.3 µg/m³, 0.7× usual Menen Menen, 4 September: 10.4 µg/m³, 1.9× usual Menen, 5 September: 11.6 µg/m³, 2.1× usual Menen, 6 September: 9.4 µg/m³, 1.7× usual Menen, 7 September: 15.3 µg/m³, 2.7× usual Menen, 8 September: 19.3 µg/m³, 3.4× usual Menen, 9 September: 25.0 µg/m³, 4.5× usual Menen, 10 September: 13.9 µg/m³, 2.5× usual Menen, 11 September: 14.5 µg/m³, 2.6× usual Menen, 12 September: 15.7 µg/m³, 2.8× usual Menen, 13 September: 7.4 µg/m³, 1.3× usual Waregem Waregem, 4 September: 10.9 µg/m³, 1.6× usual Waregem, 5 September: 10.4 µg/m³, 1.5× usual Waregem, 6 September: 9.4 µg/m³, 1.4× usual Waregem, 7 September: 14.8 µg/m³, 2.2× usual Waregem, 8 September: 18.9 µg/m³, 2.8× usual Waregem, 9 September: 25.0 µg/m³, 3.7× usual Waregem, 10 September: 15.3 µg/m³, 2.3× usual Waregem, 11 September: 16.2 µg/m³, 2.4× usual Waregem, 12 September: 21.0 µg/m³, 3.1× usual Waregem, 13 September: 7.4 µg/m³, 1.1× usual 4 Sep 5 6 7 8 9 10 11 12 13 Every counted city, in the order the episode reached them, 3 days before to 3 after. Each square is a day, coloured by that day's PM2.5; outlined: at twice the city's usual or more. Good 0–50
Moderate 51–100
Sensitive groups 101–150
Unhealthy 151–200
Very unhealthy 201–300
Hazardous 301+
Every city it reached
City Days Highest Usual Above usual
Canvey Island England, United Kingdom 3 10 September 4.9 11× Dunkirk Hauts-de-France, France 4 9 September 5.5 8.8× Zwijndrecht Flanders, Belgium 1 9 September 5.2 8.4× Clacton-on-Sea England, United Kingdom 4 8 September 4.6 8.4× Antwerp Flanders, Belgium 1 9 September 5.2 7.8× Bexley England, United Kingdom 3 10 September 4.9 7.8× Dartford England, United Kingdom 2 10 September 5.3 7.4× Dagenham England, United Kingdom 3 10 September 4.6 7.3× Beveren Flanders, Belgium 1 9 September 5.0 7.3× Saltash England, United Kingdom 1 8 September 3.1 7.2× Koksijde Flanders, Belgium 3 9 September 4.6 7.0× Aarschot Flanders, Belgium 1 9 September 4.4 7.0× Roeselare Flanders, Belgium 1 9 September 5.3 6.6× Dún Laoghaire Leinster, Ireland 1 8 September 4.4 6.3× Willebroek Flanders, Belgium 1 9 September 4.7 6.3× Norwich England, United Kingdom 1 9 September 4.7 6.0× Maldegem Flanders, Belgium 1 9 September 5.3 6.0× Evergem Flanders, Belgium 1 9 September 5.7 5.9× Grimbergen Flanders, Belgium 1 9 September 5.0 5.8× Stoke-on-Trent England, United Kingdom 1 9 September 4.7 5.7× Plymouth England, United Kingdom 1 8 September 6.4 5.7× Banbridge Northern Ireland, United Kingdom 1 8 September 3.9 5.6× London England, United Kingdom 2 10 September 6.1 5.5× Nottingham England, United Kingdom 2 9 September 6.0 5.5× Dublin Leinster, Ireland 1 8 September 4.5 5.4× Brussels Brussels Capital, Belgium 1 9 September 4.4 5.4× Canterbury England, United Kingdom 2 10 September 5.2 5.3× Kapellen Flanders, Belgium 1 9 September 5.0 5.3× Liverpool England, United Kingdom 1 9 September 4.4 5.3× Belfast Northern Ireland, United Kingdom 1 8 September 5.0 5.3× Speke England, United Kingdom 2 9 September 5.8 5.3× Lochristi Flanders, Belgium 1 9 September 5.9 5.3× Manchester England, United Kingdom 1 9 September 5.6 5.2× Birmingham England, United Kingdom 1 9 September 5.1 5.1× Gent Flanders, Belgium 1 9 September 5.1 5.0× Preston England, United Kingdom 1 9 September 4.6 5.0× Leeds England, United Kingdom 1 9 September 5.8 4.9× Menen Flanders, Belgium 1 9 September 5.6 4.5× Roubaix Hauts-de-France, France 1 9 September 6.1 4.4× Grays England, United Kingdom 2 7 September 7.6 4.3× Izegem Flanders, Belgium 1 9 September 7.4 4.1× Waregem Flanders, Belgium 1 9 September 6.8 3.7×
Daily means in µg/m³. Usual: the city's median for this time of year (its days within 21 days of the date, every year, leaving out the week around it). Above usual: its highest day against that.
Against other episodes in the United Kingdom and Belgium
Number 3 of 9 episodes in the United Kingdom and Belgium since our records began, by cities reached.
France, The Netherlands and United Kingdom, January 2023 66 France, Belgium and United Kingdom, November and December 2023 43 United Kingdom and Belgium, September 2023 42 France and Belgium, April 2023 36 Belgium and Germany, May 2023 26 Belgium and France, August 2023 15 United Kingdom, Belgium and France, June 2023 10 Flanders and Wallonia, Belgium, May 2023 10 Belgium and France, April 2023 9 Bars: cities reached; colour: the level of the episode's highest daily reading.
Use this page SmogRank, United Kingdom and Belgium, September 2023: 42 cities with PM2.5 at twice their usual or more, 7 to 10 September 2023, smogrank.com/episodes/2023-09-united-kingdom-and-belgium (accessed 2 October 2026).
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You're welcome to reuse a single chart, image or figure with this citation and a link. Terms .
An episode is a run of days when many cities close to each other (four or more within 350 km on a day, 8 or more in all) each had a daily PM2.5 mean of at least 25 µg/m³ and at least 2 times their usual for that time of year. Found in our own measurements, not picked by hand. How we find episodes . Values are each city's daily mean of its own monitors; causes are the usual kinds for a pattern like this, not a confirmed source.
