SmogRank / Episodes / France
France and Belgium, June 2026
For 1 day, on 25 June 2026, 13 cities in France, Belgium, The Netherlands and 1 more countries had PM2.5 at least twice their usual for the time of year. The worst reading was Unna, North Rhine-Westphalia, Germany: 39.0 µg/m³ on 25 June, about 4.2× its usual 9.2.
No cause named We have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached 13 in 4 countries
Days 1 25 June 2026
Worst day 25 June 13 cities counted
Furthest above usual 5.3× Beersel
Day by day
Play 25 June 13 cities at twice their usual or more
Izegem Menen Kortrijk Lille Tournai Douai Evergem Gent Arras Denain Lochristi Valenciennes Mons Saint-Quentin Beveren Zwijndrecht Brussels Willebroek Amiens Grimbergen Stabroek Antwerp Kapellen Mechelen Zaventem 's-Gravenzande Jumet Overijse Rixensart Maassluis Charleroi Spijkenisse Schiedam The Hague Rotterdam Ridderkerk Aarschot Breda Creil Beauvais Namur Reims Hillegom Mol Domont Andenne Tilburg Velserbroek Velsen-Zuid Badhoevedorp Coulommiers Dieppe IJsselstein Paris Zaanstad Amsterdam Maarssen Hasselt Houthalen Utrecht Purmerend Marche-en-Famenne Flémalle-Haute Genk Eindhoven Rouen Ans Liège Louviers Rambouillet Medemblik Évreux Barneveld Dreux Dartford Bexley Nijmegen Heerlen Venray Eupen Saint-Dizier Aachen Venlo Cambridge London Montivilliers Le Havre Esch-sur-Alzette Jülich Luxembourg Mönchengladbach Jüchen Krefeld Thionville Wesel Metz Düsseldorf Duisburg Pulheim Trier Ratingen Oberhausen Caen Borken Köln Nancy Bottrop Leverkusen Essen Enschede Dillingen Bonn Saarlouis Gelsenkirchen Wuppertal Saint-Avold Groningen Hattingen Völklingen Lunéville Saarbrücken Datteln Hagen Dortmund Neuwied Lünen Lingen Schwerte Bendorf Koblenz Lüdenscheid Münster Emden Olpe Bad Kreuznach Kaiserslautern Limburg an der Lahn Netphen Soest Birmingham Osnabrück Friesoythe Westbury Wiesbaden Strasbourg Warstein Mainz Kehl Saint Helier Rüsselsheim am Main Wetzlar Königstein im Taunus Worms Hattersheim Riedstadt Bielefeld Oldenburg Eschborn Lampertheim Ludwigshafen am Rhein Mannheim Speyer Gießen Baden-Baden Eggenstein-Leopoldshafen Frankfurt am Main Darmstadt Karlsruhe Bensheim Marburg an der Lahn Heidelberg Wiesloch Hanau am Main Delmenhorst Pforzheim Bad Wildungen Michelstadt Bremen Großostheim Rinteln Aschaffenburg Herrenberg Oyten Heilbronn Kassel Ludwigsburg Stuttgart Filderstadt Roeselare Roubaix Maldegem Knokke-Heist Unna Béthune Boulogne-sur-Mer Cherbourg Dunkirk Koksijde Calais Haarlem Beersel 22 Jun 23 24 25 26 27 28 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
Unna Unna, 22 June: no reading Unna, 23 June: no reading Unna, 24 June: 14.3 µg/m³, 1.6× usual Unna, 25 June: 39.0 µg/m³, 4.2× usual Unna, 26 June: 18.0 µg/m³, 2.0× usual Unna, 27 June: 21.4 µg/m³, 2.3× usual Unna, 28 June: 16.2 µg/m³, 1.8× usual Béthune Béthune, 22 June: no reading Béthune, 23 June: 11.9 µg/m³, 1.4× usual Béthune, 24 June: 11.4 µg/m³, 1.3× usual Béthune, 25 June: 36.7 µg/m³, 4.3× usual Béthune, 26 June: 17.3 µg/m³, 2.0× usual Béthune, 27 June: 8.6 µg/m³, 1.0× usual Béthune, 28 June: 7.1 µg/m³, 0.8× usual Dunkirk Dunkirk, 22 June: 8.4 µg/m³, 1.1× usual Dunkirk, 23 June: 9.6 µg/m³, 1.2× usual Dunkirk, 24 June: 22.0 µg/m³, 2.9× usual Dunkirk, 25 June: 34.6 µg/m³, 4.5× usual Dunkirk, 26 June: 20.6 µg/m³, 2.7× usual Dunkirk, 27 June: 13.4 µg/m³, 1.7× usual Dunkirk, 28 June: 6.5 µg/m³, 0.8× usual Calais Calais, 22 June: 9.5 µg/m³, 1.4× usual Calais, 23 June: 12.0 µg/m³, 1.8× usual Calais, 24 June: 22.7 µg/m³, 3.4× usual Calais, 25 June: 32.2 µg/m³, 4.9× usual Calais, 26 June: 19.4 µg/m³, 2.9× usual Calais, 27 June: 9.9 µg/m³, 1.5× usual Calais, 28 June: 6.2 µg/m³, 0.9× usual Boulogne-sur-Mer Boulogne-sur-Mer, 22 June: 13.2 µg/m³, 1.9× usual Boulogne-sur-Mer, 23 June: 10.4 µg/m³, 1.5× usual Boulogne-sur-Mer, 24 June: 13.7 µg/m³, 2.0× usual Boulogne-sur-Mer, 25 June: 29.9 µg/m³, 4.3× usual Boulogne-sur-Mer, 26 June: 17.9 µg/m³, 2.6× usual Boulogne-sur-Mer, 27 June: 10.6 µg/m³, 1.5× usual Boulogne-sur-Mer, 28 June: 7.2 µg/m³, 1.0× usual Koksijde Koksijde, 22 June: 8.5 µg/m³, 1.3× usual Koksijde, 23 June: 9.2 µg/m³, 1.4× usual Koksijde, 24 June: 13.3 µg/m³, 2.0× usual Koksijde, 25 June: 29.7 µg/m³, 4.5× usual Koksijde, 26 June: 16.8 µg/m³, 2.5× usual Koksijde, 27 June: 10.2 µg/m³, 1.5× usual Koksijde, 28 June: 4.8 µg/m³, 0.7× usual Knokke-Heist Knokke-Heist, 22 June: 6.4 µg/m³, 0.9× usual Knokke-Heist, 23 June: 8.2 µg/m³, 1.2× usual Knokke-Heist, 24 June: 15.2 µg/m³, 2.2× usual Knokke-Heist, 25 June: 28.1 µg/m³, 4.0× usual Knokke-Heist, 26 June: 18.6 µg/m³, 2.7× usual Knokke-Heist, 27 June: 12.3 µg/m³, 1.8× usual Knokke-Heist, 28 June: 7.4 µg/m³, 1.1× usual Maldegem Maldegem, 22 June: 7.3 µg/m³, 1.0× usual Maldegem, 23 June: 9.0 µg/m³, 1.3× usual Maldegem, 24 June: 12.9 µg/m³, 1.8× usual Maldegem, 25 June: 27.4 µg/m³, 3.9× usual Maldegem, 26 June: 18.9 µg/m³, 2.7× usual Maldegem, 27 June: 11.1 µg/m³, 1.6× usual Maldegem, 28 June: 8.2 µg/m³, 1.2× usual Beersel Beersel, 22 June: 13.8 µg/m³, 2.8× usual Beersel, 23 June: 14.3 µg/m³, 2.9× usual Beersel, 24 June: 16.1 µg/m³, 3.2× usual Beersel, 25 June: 26.5 µg/m³, 5.3× usual Beersel, 26 June: 23.8 µg/m³, 4.8× usual Beersel, 27 June: 18.9 µg/m³, 3.8× usual Beersel, 28 June: 9.0 µg/m³, 1.8× usual Roeselare Roeselare, 22 June: 10.8 µg/m³, 1.3× usual Roeselare, 23 June: 9.9 µg/m³, 1.2× usual Roeselare, 24 June: 11.1 µg/m³, 1.4× usual Roeselare, 25 June: 26.5 µg/m³, 3.3× usual Roeselare, 26 June: 17.4 µg/m³, 2.1× usual Roeselare, 27 June: 9.5 µg/m³, 1.2× usual Roeselare, 28 June: 7.2 µg/m³, 0.9× usual Roubaix Roubaix, 22 June: 15.7 µg/m³, 2.2× usual Roubaix, 23 June: 13.2 µg/m³, 1.8× usual Roubaix, 24 June: 13.2 µg/m³, 1.8× usual Roubaix, 25 June: 26.3 µg/m³, 3.7× usual Roubaix, 26 June: 18.8 µg/m³, 2.6× usual Roubaix, 27 June: 10.7 µg/m³, 1.5× usual Roubaix, 28 June: 8.1 µg/m³, 1.1× usual Haarlem Haarlem, 22 June: 0.2 µg/m³, 0.0× usual Haarlem, 23 June: 2.4 µg/m³, 0.5× usual Haarlem, 24 June: 14.8 µg/m³, 3.0× usual Haarlem, 25 June: 26.0 µg/m³, 5.2× usual Haarlem, 26 June: 17.3 µg/m³, 3.5× usual Haarlem, 27 June: 17.9 µg/m³, 3.6× usual Haarlem, 28 June: no reading Cherbourg Cherbourg, 22 June: 13.6 µg/m³, 2.4× usual Cherbourg, 23 June: 15.9 µg/m³, 2.8× usual Cherbourg, 24 June: 20.5 µg/m³, 3.6× usual Cherbourg, 25 June: 25.2 µg/m³, 4.4× usual Cherbourg, 26 June: 10.2 µg/m³, 1.8× usual Cherbourg, 27 June: 4.8 µg/m³, 0.8× usual Cherbourg, 28 June: 3.8 µg/m³, 0.7× usual 22 Jun 23 24 25 26 27 28 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
Beersel Flanders, Belgium 1 25 June 3.5 5.3× Haarlem North Holland, The Netherlands 1 25 June 3.6 5.2× Calais Hauts-de-France, France 1 25 June 6.6 4.9× Koksijde Flanders, Belgium 1 25 June 6.6 4.5× Dunkirk Hauts-de-France, France 1 25 June 7.7 4.5× Cherbourg Normandy, France 1 25 June 5.7 4.4× Béthune Hauts-de-France, France 1 25 June 8.5 4.3× Boulogne-sur-Mer Hauts-de-France, France 1 25 June 7.0 4.3× Unna North Rhine-Westphalia, Germany 1 25 June 9.2 4.2× Knokke-Heist Flanders, Belgium 1 25 June 7.0 4.0× Maldegem Flanders, Belgium 1 25 June 7.0 3.9× Roubaix Hauts-de-France, France 1 25 June 7.2 3.7× Roeselare Flanders, Belgium 1 25 June 8.1 3.3×
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 France and Belgium
Number 17 of 28 episodes in France and Belgium 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 France and Belgium, June 2026 13 Bars: cities reached; colour: the level of the episode's highest daily reading. All 28 .
Use this page SmogRank, France and Belgium, June 2026: 13 cities with PM2.5 at twice their usual or more, 25 June 2026, smogrank.com/episodes/2026-06-france-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.
