SmogRank / Episodes / Belgium
Belgium and France, October 2025
For 2 days, from 11 to 12 October 2025, 10 cities in Belgium, France, Germany and 1 more countries had PM2.5 at least twice their usual for the time of year. The worst reading was Roeselare, Flanders, Belgium: 30.7 µg/m³ on 11 October, about 4.1× its usual 7.4.
No cause named We have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached 10 in 4 countries
Days 2 11 to 12 October 2025
Worst day 11 October 6 cities counted
Furthest above usual 5.8× Cambridge
Day by day
Play 11 October 6 cities at twice their usual or more
Gent Evergem Beveren Willebroek Zwijndrecht Grimbergen Brussels Stabroek Mechelen Zaventem Kapellen Mons Rixensart Tournai Kortrijk Jumet Knokke-Heist Charleroi Valenciennes Aarschot Spijkenisse Roubaix Menen Maassluis Denain Breda Schiedam 's-Gravenzande Rotterdam Ridderkerk Namur The Hague Douai Mol Tilburg Andenne Koksijde Hasselt Hillegom Saint-Quentin Houthalen IJsselstein Béthune Haarlem Badhoevedorp Maarssen Genk Flémalle-Haute Velserbroek Utrecht Eindhoven Velsen-Zuid Ans Marche-en-Famenne Amsterdam Dunkirk Zaanstad Liège Purmerend Reims Barneveld Heerlen Nijmegen Venray Medemblik Eupen Aachen Calais Venlo Creil Jülich Boulogne-sur-Mer Coulommiers Mönchengladbach Beauvais Jüchen Esch-sur-Alzette Krefeld Luxembourg Saint-Dizier Domont Wesel Paris Thionville Düsseldorf Duisburg Pulheim Ratingen Oberhausen Metz Clacton-on-Sea Trier Köln Borken Bottrop Leverkusen Essen Norwich Bonn Enschede Gelsenkirchen Wuppertal Hattingen Dillingen Rambouillet Nancy Rouen Saint-Avold Louviers Groningen Völklingen Datteln Canvey Island Gillingham Évreux Dreux Hagen Dortmund Saarbrücken Neuwied Schwerte Lüdenscheid Bendorf Lingen Koblenz Unna Münster Newmarket Dartford Bexley Seaford Emden Bad Kreuznach Montivilliers Kaiserslautern Netphen Limburg an der Lahn Brighton London Soest Le Havre Osnabrück Friesoythe Wiesbaden Warstein Mainz Hayes Luton Wetzlar Rüsselsheim am Main Königstein im Taunus Worms Hattersheim Bielefeld Riedstadt Eschborn Gießen Lampertheim Oldenburg Caen Ludwigshafen am Rhein Mannheim Speyer Frankfurt am Main Marburg an der Lahn Darmstadt Eggenstein-Leopoldshafen Bensheim Baden-Baden Karlsruhe Reading Heidelberg Northampton Hanau am Main Wiesloch Delmenhorst Portsmouth Bad Wildungen Pforzheim Michelstadt Großostheim Rinteln Bremen Aschaffenburg Oxford Leicester Southampton Oyten Herrenberg Nottingham Andover Kassel Heilbronn Ludwigsburg Royal Leamington Spa Stuttgart Uslar Fulda Filderstadt Derby Cherbourg Chesterfield Witzenhausen Walsrode Hannover Lauda-Königshofen Sheffield Göttingen Birmingham Hildesheim Schwäbisch Hall Würzburg Westbury Buxtehude Cannock High Peak Duderstadt Eisenach Saint Helier Meiningen Mühlhausen Stoke-on-Trent Aalen Goslar Salzgitter Cheadle Hulme Manchester Lüneburg Irlam Izegem Lochristi Lille Antwerp Amiens Maldegem Roeselare Dieppe Olpe Cambridge 8 Oct 9 10 11 12 13 14 15 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
Roeselare Roeselare, 8 October: 8.4 µg/m³, 1.1× usual Roeselare, 9 October: 7.0 µg/m³, 0.9× usual Roeselare, 10 October: 15.6 µg/m³, 2.1× usual Roeselare, 11 October: 30.7 µg/m³, 4.1× usual Roeselare, 12 October: 16.9 µg/m³, 2.3× usual Roeselare, 13 October: 6.5 µg/m³, 0.9× usual Roeselare, 14 October: 10.6 µg/m³, 1.4× usual Roeselare, 15 October: no reading Izegem Izegem, 8 October: 10.7 µg/m³, 1.1× usual Izegem, 9 October: 7.0 µg/m³, 0.7× usual Izegem, 10 October: 15.0 µg/m³, 1.6× usual Izegem, 11 October: 30.5 µg/m³, 3.2× usual Izegem, 12 October: 18.7 µg/m³, 2.0× usual Izegem, 13 October: 7.5 µg/m³, 0.8× usual Izegem, 14 October: 10.0 µg/m³, 1.1× usual Izegem, 15 October: no reading Olpe Olpe, 8 October: 7.4 µg/m³, 1.5× usual Olpe, 9 October: 14.7 µg/m³, 2.9× usual Olpe, 10 October: 23.9 µg/m³, 4.8× usual Olpe, 11 October: 27.2 µg/m³, 5.4× usual Olpe, 12 October: 14.9 µg/m³, 3.0× usual Olpe, 13 October: 3.5 µg/m³, 0.7× usual Olpe, 14 October: 6.4 µg/m³, 1.3× usual Olpe, 15 October: 8.1 µg/m³, 1.6× usual Antwerp Antwerp, 8 October: 10.3 µg/m³, 1.5× usual Antwerp, 9 October: 6.6 µg/m³, 0.9× usual Antwerp, 10 October: 12.3 µg/m³, 1.8× usual Antwerp, 11 October: 26.8 µg/m³, 3.8× usual Antwerp, 12 October: 14.2 µg/m³, 2.0× usual Antwerp, 13 October: 3.6 µg/m³, 0.5× usual Antwerp, 14 October: 5.9 µg/m³, 0.8× usual Antwerp, 15 October: no reading Maldegem Maldegem, 8 October: 7.4 µg/m³, 1.2× usual Maldegem, 9 October: 5.7 µg/m³, 0.9× usual Maldegem, 10 October: 11.2 µg/m³, 1.7× usual Maldegem, 11 October: 26.0 µg/m³, 4.1× usual Maldegem, 12 October: 9.4 µg/m³, 1.5× usual Maldegem, 13 October: 3.0 µg/m³, 0.5× usual Maldegem, 14 October: 6.1 µg/m³, 1.0× usual Maldegem, 15 October: no reading Lochristi Lochristi, 8 October: 9.8 µg/m³, 1.3× usual Lochristi, 9 October: 6.7 µg/m³, 0.9× usual Lochristi, 10 October: 12.7 µg/m³, 1.7× usual Lochristi, 11 October: 25.5 µg/m³, 3.4× usual Lochristi, 12 October: 13.7 µg/m³, 1.9× usual Lochristi, 13 October: 4.3 µg/m³, 0.6× usual Lochristi, 14 October: 6.7 µg/m³, 0.9× usual Lochristi, 15 October: no reading Cambridge Cambridge, 8 October: 2.5 µg/m³, 0.5× usual Cambridge, 9 October: 5.0 µg/m³, 1.0× usual Cambridge, 10 October: 6.8 µg/m³, 1.4× usual Cambridge, 11 October: 13.4 µg/m³, 2.7× usual Cambridge, 12 October: 28.9 µg/m³, 5.8× usual Cambridge, 13 October: 14.3 µg/m³, 2.9× usual Cambridge, 14 October: 3.2 µg/m³, 0.6× usual Cambridge, 15 October: 1.4 µg/m³, 0.3× usual Dieppe Dieppe, 8 October: 8.4 µg/m³, 1.3× usual Dieppe, 9 October: 6.3 µg/m³, 1.0× usual Dieppe, 10 October: 10.5 µg/m³, 1.7× usual Dieppe, 11 October: 13.2 µg/m³, 2.1× usual Dieppe, 12 October: 27.3 µg/m³, 4.3× usual Dieppe, 13 October: 11.1 µg/m³, 1.8× usual Dieppe, 14 October: 8.5 µg/m³, 1.3× usual Dieppe, 15 October: no reading Amiens Amiens, 8 October: 7.5 µg/m³, 1.2× usual Amiens, 9 October: 7.5 µg/m³, 1.2× usual Amiens, 10 October: 13.1 µg/m³, 2.0× usual Amiens, 11 October: 14.5 µg/m³, 2.2× usual Amiens, 12 October: 25.4 µg/m³, 3.9× usual Amiens, 13 October: 10.0 µg/m³, 1.5× usual Amiens, 14 October: 10.6 µg/m³, 1.6× usual Amiens, 15 October: no reading Lille Lille, 8 October: 11.0 µg/m³, 1.7× usual Lille, 9 October: 9.9 µg/m³, 1.5× usual Lille, 10 October: 15.6 µg/m³, 2.4× usual Lille, 11 October: 24.5 µg/m³, 3.8× usual Lille, 12 October: 25.0 µg/m³, 3.8× usual Lille, 13 October: 7.0 µg/m³, 1.1× usual Lille, 14 October: 11.1 µg/m³, 1.7× usual Lille, 15 October: no reading 8 Oct 9 10 11 12 13 14 15 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
Cambridge England, United Kingdom 1 12 October 2.1 5.8× Olpe North Rhine-Westphalia, Germany 1 11 October 3.4 5.4× Dieppe Normandy, France 1 12 October 6.3 4.3× Roeselare Flanders, Belgium 1 11 October 7.4 4.1× Maldegem Flanders, Belgium 1 11 October 6.4 4.1× Amiens Hauts-de-France, France 1 12 October 6.5 3.9× Lille Hauts-de-France, France 1 12 October 6.5 3.8× Antwerp Flanders, Belgium 1 11 October 7.0 3.8× Lochristi Flanders, Belgium 1 11 October 7.4 3.4× Izegem Flanders, Belgium 1 11 October 9.4 3.2×
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 Belgium and France
Number 20 of 28 episodes in Belgium and France since our records began, by cities reached.
Central Europe, February and March 2023 274 Central Europe, December 2025 to January 2026 170 Western Europe, March 2023 119 Southern Europe, December 2023 97 North-eastern Spain and France, February 2023 72 France, The Netherlands and United Kingdom, January 2023 66 Central Europe, June 2025 63 Western Europe, January 2025 50 France, Belgium and United Kingdom, November and December 2023 43 United Kingdom and Belgium, September 2023 42 France and Belgium, April 2023 36 France, July 2026 26 Belgium and France, October 2025 10 Bars: cities reached; colour: the level of the episode's highest daily reading. All 28 .
Use this page SmogRank, Belgium and France, October 2025: 10 cities with PM2.5 at twice their usual or more, 11 to 12 October 2025, smogrank.com/episodes/2025-10-belgium-and-france (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.
