SmogRank / Episodes / Slovakia
South-eastern Europe, December 2023 to January 2024
For 5 days, from 28 December 2023 to 1 January 2024, 34 cities in Slovakia, Greece, Bulgaria and 7 more countries had PM2.5 at least twice their usual for the time of year. The worst reading was Banja Luka, Srpska, Bosnia and Herzegovina: 134.0 µg/m³ on 28 December, about 2.4× its usual 55.8.
No cause named We have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached 34 in 10 countries
Days 5 28 December 2023 to 1 January 2024
Worst day 29 December 14 cities counted
Furthest above usual 5.1× Pristina
Day by day
Play 29 December 14 cities at twice their usual or more
Belgrade Tetovo Pljevlja Ilinden Podgorica Novi Sad Kochani Bar Kavadarci Bitola Craiova Liberpolis Pécs Dunaújváros Ceglie Messapica Gabrovo Miskolc Veszprém Dej Kazincbarcika Esztergom Košice Győr Vranov nad Topľou Spišská Nová Ves Prešov Humenné Poprad Prievidza Ružomberok Martin Asprópyrgos Karlova Ves Žilina Khalándrion Jasło Baden Mödling Graz Benevento Vienna Perchtoldsdorf Przemyśl Třinec Zlín Klosterneuburg Český Těšín Cieszyn Valašské Meziříčí Frýdek-Místek Salerno Rijeka Havířov Kroměříž Ostrava Přerov Wolfsberg Caserta Sankt Pölten Olomouc Naples Židenice Brno Civitanova Marche Znojmo Klagenfurt am Wörthersee Ancona Falconara Marittima Amstetten Jesi Steyr Ansfelden Linz Wels České Budějovice Passau Pilsen Senica Trnava Szeged Sarajevo Sofia Pátra Nitra Skopje Banská Bystrica Handlová Partizánske Žiar nad Hronom Zvolen Bratislava Traun Banja Luka Volos Botevgrad Cluj-Napoca Snina Piraeus Thessaloníki Trenčín Nyíregyháza Ruse Haskovo Acharnés Veles Niš Pylaía Athens Bucharest Iaşi Pristina 25 Dec 26 27 28 29 30 31 1 Jan 2 3 4 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
Niš Niš, 25 December: 126.5 µg/m³, 3.1× usual Niš, 26 December: 87.3 µg/m³, 2.1× usual Niš, 27 December: 75.6 µg/m³, 1.8× usual Niš, 28 December: 110.5 µg/m³, 2.7× usual Niš, 29 December: 96.6 µg/m³, 2.4× usual Niš, 30 December: 93.8 µg/m³, 2.3× usual Niš, 31 December: 92.3 µg/m³, 2.2× usual Niš, 1 January: 59.4 µg/m³, 1.4× usual Niš, 2 January: 57.7 µg/m³, 1.4× usual Niš, 3 January: 118.0 µg/m³, 2.9× usual Niš, 4 January: 68.6 µg/m³, 1.7× usual Skopje Skopje, 25 December: 102.5 µg/m³, 2.0× usual Skopje, 26 December: 102.4 µg/m³, 2.0× usual Skopje, 27 December: 88.1 µg/m³, 1.8× usual Skopje, 28 December: 80.6 µg/m³, 1.6× usual Skopje, 29 December: 97.4 µg/m³, 1.9× usual Skopje, 30 December: 102.6 µg/m³, 2.0× usual Skopje, 31 December: 105.5 µg/m³, 2.1× usual Skopje, 1 January: 109.0 µg/m³, 2.2× usual Skopje, 2 January: 86.1 µg/m³, 1.7× usual Skopje, 3 January: 58.3 µg/m³, 1.2× usual Skopje, 4 January: 48.2 µg/m³, 1.0× usual Veles Veles, 25 December: 90.6 µg/m³, 1.8× usual Veles, 26 December: 80.1 µg/m³, 1.6× usual Veles, 27 December: 43.7 µg/m³, 0.9× usual Veles, 28 December: 71.9 µg/m³, 1.4× usual Veles, 29 December: 80.7 µg/m³, 1.6× usual Veles, 30 December: 134.0 µg/m³, 2.7× usual Veles, 31 December: 126.0 µg/m³, 2.5× usual Veles, 1 January: 89.7 µg/m³, 1.8× usual Veles, 2 January: 76.8 µg/m³, 1.5× usual Veles, 3 January: 60.5 µg/m³, 1.2× usual Veles, 4 January: 60.8 µg/m³, 1.2× usual Athens Athens, 25 December: 41.9 µg/m³, 2.1× usual Athens, 26 December: 42.5 µg/m³, 2.1× usual Athens, 27 December: 28.7 µg/m³, 1.4× usual Athens, 28 December: 42.1 µg/m³, 2.1× usual Athens, 29 December: 48.2 µg/m³, 2.4× usual Athens, 30 December: 48.1 µg/m³, 2.4× usual Athens, 31 December: 48.0 µg/m³, 2.4× usual Athens, 1 January: 60.3 µg/m³, 3.0× usual Athens, 2 January: 28.5 µg/m³, 1.4× usual Athens, 3 January: 12.2 µg/m³, 0.6× usual Athens, 4 January: 11.9 µg/m³, 0.6× usual Piraeus Piraeus, 25 December: 39.3 µg/m³, 2.8× usual Piraeus, 26 December: 30.8 µg/m³, 2.2× usual Piraeus, 27 December: 18.1 µg/m³, 1.3× usual Piraeus, 28 December: 28.6 µg/m³, 2.0× usual Piraeus, 29 December: 26.2 µg/m³, 1.9× usual Piraeus, 30 December: 28.0 µg/m³, 2.0× usual Piraeus, 31 December: 24.7 µg/m³, 1.8× usual Piraeus, 1 January: 36.2 µg/m³, 2.6× usual Piraeus, 2 January: 24.8 µg/m³, 1.8× usual Piraeus, 3 January: 10.4 µg/m³, 0.7× usual Piraeus, 4 January: 8.3 µg/m³, 0.6× usual Acharnés Acharnés, 25 December: 27.4 µg/m³, 1.9× usual Acharnés, 26 December: 21.3 µg/m³, 1.5× usual Acharnés, 27 December: 17.5 µg/m³, 1.2× usual Acharnés, 28 December: 19.8 µg/m³, 1.4× usual Acharnés, 29 December: 25.1 µg/m³, 1.8× usual Acharnés, 30 December: 26.3 µg/m³, 1.9× usual Acharnés, 31 December: 30.7 µg/m³, 2.2× usual Acharnés, 1 January: 38.5 µg/m³, 2.7× usual Acharnés, 2 January: 23.4 µg/m³, 1.6× usual Acharnés, 3 January: 12.1 µg/m³, 0.9× usual Acharnés, 4 January: 11.3 µg/m³, 0.8× usual Banja Luka Banja Luka, 25 December: 71.4 µg/m³, 1.3× usual Banja Luka, 26 December: 108.0 µg/m³, 1.9× usual Banja Luka, 27 December: 99.8 µg/m³, 1.8× usual Banja Luka, 28 December: 134.0 µg/m³, 2.4× usual Banja Luka, 29 December: 117.0 µg/m³, 2.1× usual Banja Luka, 30 December: 84.3 µg/m³, 1.5× usual Banja Luka, 31 December: 26.2 µg/m³, 0.5× usual Banja Luka, 1 January: 44.4 µg/m³, 0.8× usual Banja Luka, 2 January: 67.1 µg/m³, 1.2× usual Banja Luka, 3 January: 5.9 µg/m³, 0.1× usual Banja Luka, 4 January: 30.7 µg/m³, 0.6× usual Pristina Pristina, 25 December: 33.8 µg/m³, 1.7× usual Pristina, 26 December: 38.2 µg/m³, 1.9× usual Pristina, 27 December: 30.9 µg/m³, 1.5× usual Pristina, 28 December: 63.0 µg/m³, 3.1× usual Pristina, 29 December: 55.3 µg/m³, 2.7× usual Pristina, 30 December: 81.9 µg/m³, 4.0× usual Pristina, 31 December: 104.0 µg/m³, 5.1× usual Pristina, 1 January: 87.8 µg/m³, 4.3× usual Pristina, 2 January: 25.1 µg/m³, 1.2× usual Pristina, 3 January: no reading Pristina, 4 January: 20.9 µg/m³, 1.0× usual Sarajevo Sarajevo, 25 December: 52.5 µg/m³, 0.9× usual Sarajevo, 26 December: 50.9 µg/m³, 0.9× usual Sarajevo, 27 December: 72.0 µg/m³, 1.2× usual Sarajevo, 28 December: 110.0 µg/m³, 1.9× usual Sarajevo, 29 December: 51.3 µg/m³, 0.9× usual Sarajevo, 30 December: 120.0 µg/m³, 2.1× usual Sarajevo, 31 December: 120.0 µg/m³, 2.1× usual Sarajevo, 1 January: 35.4 µg/m³, 0.6× usual Sarajevo, 2 January: 37.7 µg/m³, 0.7× usual Sarajevo, 3 January: 28.9 µg/m³, 0.5× usual Sarajevo, 4 January: 35.4 µg/m³, 0.6× usual Nyíregyháza Nyíregyháza, 25 December: 8.5 µg/m³, 0.4× usual Nyíregyháza, 26 December: 10.0 µg/m³, 0.5× usual Nyíregyháza, 27 December: 15.3 µg/m³, 0.7× usual Nyíregyháza, 28 December: 19.2 µg/m³, 0.9× usual Nyíregyháza, 29 December: 55.0 µg/m³, 2.6× usual Nyíregyháza, 30 December: 31.7 µg/m³, 1.5× usual Nyíregyháza, 31 December: 33.3 µg/m³, 1.5× usual Nyíregyháza, 1 January: 13.7 µg/m³, 0.6× usual Nyíregyháza, 2 January: 11.4 µg/m³, 0.5× usual Nyíregyháza, 3 January: 7.1 µg/m³, 0.3× usual Nyíregyháza, 4 January: 8.3 µg/m³, 0.4× usual Iaşi Iaşi, 25 December: 12.0 µg/m³, 0.6× usual Iaşi, 26 December: 11.9 µg/m³, 0.6× usual Iaşi, 27 December: 17.0 µg/m³, 0.9× usual Iaşi, 28 December: 27.7 µg/m³, 1.5× usual Iaşi, 29 December: 50.4 µg/m³, 2.7× usual Iaşi, 30 December: 67.7 µg/m³, 3.6× usual Iaşi, 31 December: 49.6 µg/m³, 2.7× usual Iaşi, 1 January: 32.6 µg/m³, 1.8× usual Iaşi, 2 January: 12.5 µg/m³, 0.7× usual Iaşi, 3 January: 17.3 µg/m³, 0.9× usual Iaşi, 4 January: 17.3 µg/m³, 0.9× usual Zvolen Zvolen, 25 December: 5.8 µg/m³, 0.3× usual Zvolen, 26 December: 4.9 µg/m³, 0.3× usual Zvolen, 27 December: 9.7 µg/m³, 0.6× usual Zvolen, 28 December: 23.7 µg/m³, 1.4× usual Zvolen, 29 December: 38.7 µg/m³, 2.2× usual Zvolen, 30 December: 31.6 µg/m³, 1.8× usual Zvolen, 31 December: 33.5 µg/m³, 1.9× usual Zvolen, 1 January: 31.5 µg/m³, 1.8× usual Zvolen, 2 January: 12.7 µg/m³, 0.7× usual Zvolen, 3 January: 13.1 µg/m³, 0.8× usual Zvolen, 4 January: 3.8 µg/m³, 0.2× usual Banská Bystrica Banská Bystrica, 25 December: 5.6 µg/m³, 0.3× usual Banská Bystrica, 26 December: 5.5 µg/m³, 0.3× usual Banská Bystrica, 27 December: 9.0 µg/m³, 0.5× usual Banská Bystrica, 28 December: 22.0 µg/m³, 1.3× usual Banská Bystrica, 29 December: 35.5 µg/m³, 2.2× usual Banská Bystrica, 30 December: 23.9 µg/m³, 1.4× usual Banská Bystrica, 31 December: 29.8 µg/m³, 1.8× usual Banská Bystrica, 1 January: 25.9 µg/m³, 1.6× usual Banská Bystrica, 2 January: 8.9 µg/m³, 0.5× usual Banská Bystrica, 3 January: 12.7 µg/m³, 0.8× usual Banská Bystrica, 4 January: 6.0 µg/m³, 0.4× usual Traun Traun, 25 December: 3.3 µg/m³, 0.2× usual Traun, 26 December: 4.9 µg/m³, 0.3× usual Traun, 27 December: 10.0 µg/m³, 0.7× usual Traun, 28 December: 25.9 µg/m³, 1.7× usual Traun, 29 December: 35.3 µg/m³, 2.3× usual Traun, 30 December: 14.8 µg/m³, 1.0× usual Traun, 31 December: 19.1 µg/m³, 1.2× usual Traun, 1 January: 14.9 µg/m³, 1.0× usual Traun, 2 January: 11.9 µg/m³, 0.8× usual Traun, 3 January: 11.2 µg/m³, 0.7× usual Traun, 4 January: 1.4 µg/m³, 0.1× usual Partizánske Partizánske, 25 December: 5.8 µg/m³, 0.4× usual Partizánske, 26 December: 7.5 µg/m³, 0.5× usual Partizánske, 27 December: 7.9 µg/m³, 0.5× usual Partizánske, 28 December: 21.9 µg/m³, 1.4× usual Partizánske, 29 December: 35.2 µg/m³, 2.2× usual Partizánske, 30 December: 32.5 µg/m³, 2.0× usual Partizánske, 31 December: 18.9 µg/m³, 1.2× usual Partizánske, 1 January: 16.1 µg/m³, 1.0× usual Partizánske, 2 January: 7.9 µg/m³, 0.5× usual Partizánske, 3 January: 8.4 µg/m³, 0.5× usual Partizánske, 4 January: 2.3 µg/m³, 0.1× usual Trnava Trnava, 25 December: 2.4 µg/m³, 0.1× usual Trnava, 26 December: 7.7 µg/m³, 0.5× usual Trnava, 27 December: 6.7 µg/m³, 0.4× usual Trnava, 28 December: 22.9 µg/m³, 1.4× usual Trnava, 29 December: 34.4 µg/m³, 2.1× usual Trnava, 30 December: 26.5 µg/m³, 1.6× usual Trnava, 31 December: 21.1 µg/m³, 1.3× usual Trnava, 1 January: 14.9 µg/m³, 0.9× usual Trnava, 2 January: 10.8 µg/m³, 0.7× usual Trnava, 3 January: 9.1 µg/m³, 0.6× usual Trnava, 4 January: 4.0 µg/m³, 0.2× usual Trenčín Trenčín, 25 December: 5.0 µg/m³, 0.3× usual Trenčín, 26 December: 9.9 µg/m³, 0.7× usual Trenčín, 27 December: 10.4 µg/m³, 0.7× usual Trenčín, 28 December: 17.8 µg/m³, 1.2× usual Trenčín, 29 December: 33.5 µg/m³, 2.3× usual Trenčín, 30 December: 37.8 µg/m³, 2.6× usual Trenčín, 31 December: 19.5 µg/m³, 1.4× usual Trenčín, 1 January: 14.9 µg/m³, 1.0× usual Trenčín, 2 January: 10.3 µg/m³, 0.7× usual Trenčín, 3 January: 10.3 µg/m³, 0.7× usual Trenčín, 4 January: 5.1 µg/m³, 0.4× usual Žiar nad Hronom Žiar nad Hronom, 25 December: 1.4 µg/m³, 0.1× usual Žiar nad Hronom, 26 December: 2.7 µg/m³, 0.2× usual Žiar nad Hronom, 27 December: 6.0 µg/m³, 0.4× usual Žiar nad Hronom, 28 December: 15.8 µg/m³, 1.1× usual Žiar nad Hronom, 29 December: 31.8 µg/m³, 2.2× usual Žiar nad Hronom, 30 December: 15.1 µg/m³, 1.0× usual Žiar nad Hronom, 31 December: 14.8 µg/m³, 1.0× usual Žiar nad Hronom, 1 January: 13.5 µg/m³, 0.9× usual Žiar nad Hronom, 2 January: 10.4 µg/m³, 0.7× usual Žiar nad Hronom, 3 January: 5.0 µg/m³, 0.3× usual Žiar nad Hronom, 4 January: 2.9 µg/m³, 0.2× usual Szeged Szeged, 25 December: 17.9 µg/m³, 1.2× usual Szeged, 26 December: 13.7 µg/m³, 0.9× usual Szeged, 27 December: 10.4 µg/m³, 0.7× usual Szeged, 28 December: 18.5 µg/m³, 1.3× usual Szeged, 29 December: 30.5 µg/m³, 2.1× usual Szeged, 30 December: 30.5 µg/m³, 2.1× usual Szeged, 31 December: 26.8 µg/m³, 1.8× usual Szeged, 1 January: 19.1 µg/m³, 1.3× usual Szeged, 2 January: 8.7 µg/m³, 0.6× usual Szeged, 3 January: 10.7 µg/m³, 0.7× usual Szeged, 4 January: 11.8 µg/m³, 0.8× usual Handlová Handlová, 25 December: 2.4 µg/m³, 0.2× usual Handlová, 26 December: 3.1 µg/m³, 0.2× usual Handlová, 27 December: 10.8 µg/m³, 0.8× usual Handlová, 28 December: 26.7 µg/m³, 2.0× usual Handlová, 29 December: 30.4 µg/m³, 2.2× usual Handlová, 30 December: 26.1 µg/m³, 1.9× usual Handlová, 31 December: 12.9 µg/m³, 0.9× usual Handlová, 1 January: 11.2 µg/m³, 0.8× usual Handlová, 2 January: 6.1 µg/m³, 0.4× usual Handlová, 3 January: 4.6 µg/m³, 0.3× usual Handlová, 4 January: 2.0 µg/m³, 0.1× usual Bratislava Bratislava, 25 December: 2.1 µg/m³, 0.2× usual Bratislava, 26 December: 8.4 µg/m³, 0.7× usual Bratislava, 27 December: 5.8 µg/m³, 0.5× usual Bratislava, 28 December: 15.0 µg/m³, 1.2× usual Bratislava, 29 December: 29.1 µg/m³, 2.3× usual Bratislava, 30 December: 16.5 µg/m³, 1.3× usual Bratislava, 31 December: 23.9 µg/m³, 1.9× usual Bratislava, 1 January: 8.2 µg/m³, 0.7× usual Bratislava, 2 January: 9.2 µg/m³, 0.7× usual Bratislava, 3 January: 5.8 µg/m³, 0.5× usual Bratislava, 4 January: 3.1 µg/m³, 0.2× usual Senica Senica, 25 December: 10.6 µg/m³, 0.8× usual Senica, 26 December: 4.6 µg/m³, 0.3× usual Senica, 27 December: 6.8 µg/m³, 0.5× usual Senica, 28 December: 17.0 µg/m³, 1.3× usual Senica, 29 December: 27.0 µg/m³, 2.0× usual Senica, 30 December: 18.7 µg/m³, 1.4× usual Senica, 31 December: 20.4 µg/m³, 1.5× usual Senica, 1 January: 13.7 µg/m³, 1.0× usual Senica, 2 January: 9.3 µg/m³, 0.7× usual Senica, 3 January: 5.5 µg/m³, 0.4× usual Senica, 4 January: 3.1 µg/m³, 0.2× usual Snina Snina, 25 December: 7.2 µg/m³, 0.7× usual Snina, 26 December: 11.4 µg/m³, 1.1× usual Snina, 27 December: 4.6 µg/m³, 0.5× usual Snina, 28 December: 11.2 µg/m³, 1.1× usual Snina, 29 December: 25.3 µg/m³, 2.5× usual Snina, 30 December: 24.0 µg/m³, 2.4× usual Snina, 31 December: 16.0 µg/m³, 1.6× usual Snina, 1 January: 8.8 µg/m³, 0.9× usual Snina, 2 January: 6.8 µg/m³, 0.7× usual Snina, 3 January: 8.3 µg/m³, 0.8× usual Snina, 4 January: 8.8 µg/m³, 0.9× usual Botevgrad Botevgrad, 25 December: 10.2 µg/m³, 0.4× usual Botevgrad, 26 December: 23.7 µg/m³, 1.0× usual Botevgrad, 27 December: 25.9 µg/m³, 1.1× usual Botevgrad, 28 December: 34.2 µg/m³, 1.5× usual Botevgrad, 29 December: 30.9 µg/m³, 1.3× usual Botevgrad, 30 December: 57.3 µg/m³, 2.5× usual Botevgrad, 31 December: 47.4 µg/m³, 2.1× usual Botevgrad, 1 January: 26.4 µg/m³, 1.1× usual Botevgrad, 2 January: 21.6 µg/m³, 0.9× usual Botevgrad, 3 January: 15.8 µg/m³, 0.7× usual Botevgrad, 4 January: 16.8 µg/m³, 0.7× usual Thessaloníki Thessaloníki, 25 December: 45.9 µg/m³, 1.8× usual Thessaloníki, 26 December: 40.6 µg/m³, 1.6× usual Thessaloníki, 27 December: 32.7 µg/m³, 1.3× usual Thessaloníki, 28 December: 42.4 µg/m³, 1.7× usual Thessaloníki, 29 December: 46.7 µg/m³, 1.8× usual Thessaloníki, 30 December: 53.6 µg/m³, 2.1× usual Thessaloníki, 31 December: 47.2 µg/m³, 1.9× usual Thessaloníki, 1 January: 65.0 µg/m³, 2.6× usual Thessaloníki, 2 January: 51.5 µg/m³, 2.0× usual Thessaloníki, 3 January: 55.3 µg/m³, 2.2× usual Thessaloníki, 4 January: 36.4 µg/m³, 1.4× usual Cluj-Napoca Cluj-Napoca, 25 December: 20.5 µg/m³, 0.9× usual Cluj-Napoca, 26 December: 16.7 µg/m³, 0.7× usual Cluj-Napoca, 27 December: 22.7 µg/m³, 1.0× usual Cluj-Napoca, 28 December: 37.7 µg/m³, 1.7× usual Cluj-Napoca, 29 December: 44.1 µg/m³, 1.9× usual Cluj-Napoca, 30 December: 49.4 µg/m³, 2.2× usual Cluj-Napoca, 31 December: 58.0 µg/m³, 2.5× usual Cluj-Napoca, 1 January: 55.4 µg/m³, 2.4× usual Cluj-Napoca, 2 January: 16.0 µg/m³, 0.7× usual Cluj-Napoca, 3 January: 15.2 µg/m³, 0.7× usual Cluj-Napoca, 4 January: 21.1 µg/m³, 0.9× usual Nitra Nitra, 25 December: 6.1 µg/m³, 0.4× usual Nitra, 26 December: 8.7 µg/m³, 0.6× usual Nitra, 27 December: 5.7 µg/m³, 0.4× usual Nitra, 28 December: 18.4 µg/m³, 1.3× usual Nitra, 29 December: 27.4 µg/m³, 1.9× usual Nitra, 30 December: 31.8 µg/m³, 2.2× usual Nitra, 31 December: 22.0 µg/m³, 1.5× usual Nitra, 1 January: 13.7 µg/m³, 0.9× usual Nitra, 2 January: 9.9 µg/m³, 0.7× usual Nitra, 3 January: 8.4 µg/m³, 0.6× usual Nitra, 4 January: 4.4 µg/m³, 0.3× usual Volos Volos, 25 December: 43.0 µg/m³, 1.5× usual Volos, 26 December: 36.8 µg/m³, 1.3× usual Volos, 27 December: 41.6 µg/m³, 1.5× usual Volos, 28 December: 37.5 µg/m³, 1.3× usual Volos, 29 December: 40.5 µg/m³, 1.4× usual Volos, 30 December: 56.9 µg/m³, 2.0× usual Volos, 31 December: 57.6 µg/m³, 2.1× usual Volos, 1 January: 69.9 µg/m³, 2.5× usual Volos, 2 January: 64.2 µg/m³, 2.3× usual Volos, 3 January: 39.5 µg/m³, 1.4× usual Volos, 4 January: 24.2 µg/m³, 0.9× usual Haskovo Haskovo, 25 December: 31.9 µg/m³, 1.1× usual Haskovo, 26 December: 25.9 µg/m³, 0.9× usual Haskovo, 27 December: 19.6 µg/m³, 0.7× usual Haskovo, 28 December: 30.3 µg/m³, 1.1× usual Haskovo, 29 December: 41.7 µg/m³, 1.5× usual Haskovo, 30 December: 42.9 µg/m³, 1.5× usual Haskovo, 31 December: 55.0 µg/m³, 1.9× usual Haskovo, 1 January: 76.1 µg/m³, 2.7× usual Haskovo, 2 January: 72.4 µg/m³, 2.5× usual Haskovo, 3 January: 58.6 µg/m³, 2.0× usual Haskovo, 4 January: 31.9 µg/m³, 1.1× usual Bucharest Bucharest, 25 December: 8.5 µg/m³, 0.5× usual Bucharest, 26 December: 11.9 µg/m³, 0.6× usual Bucharest, 27 December: 16.4 µg/m³, 0.9× usual Bucharest, 28 December: 20.7 µg/m³, 1.1× usual Bucharest, 29 December: 28.4 µg/m³, 1.5× usual Bucharest, 30 December: 21.6 µg/m³, 1.2× usual Bucharest, 31 December: 43.5 µg/m³, 2.3× usual Bucharest, 1 January: 61.3 µg/m³, 3.3× usual Bucharest, 2 January: 17.5 µg/m³, 0.9× usual Bucharest, 3 January: 13.6 µg/m³, 0.7× usual Bucharest, 4 January: 23.5 µg/m³, 1.3× usual Ruse Ruse, 25 December: 8.4 µg/m³, 0.4× usual Ruse, 26 December: 15.9 µg/m³, 0.9× usual Ruse, 27 December: 9.2 µg/m³, 0.5× usual Ruse, 28 December: 35.6 µg/m³, 1.9× usual Ruse, 29 December: 20.5 µg/m³, 1.1× usual Ruse, 30 December: 18.6 µg/m³, 1.0× usual Ruse, 31 December: 30.0 µg/m³, 1.6× usual Ruse, 1 January: 49.7 µg/m³, 2.7× usual Ruse, 2 January: 10.6 µg/m³, 0.6× usual Ruse, 3 January: 11.4 µg/m³, 0.6× usual Ruse, 4 January: no reading Pátra Pátra, 25 December: 19.0 µg/m³, 0.8× usual Pátra, 26 December: 23.8 µg/m³, 1.1× usual Pátra, 27 December: 26.0 µg/m³, 1.2× usual Pátra, 28 December: 28.9 µg/m³, 1.3× usual Pátra, 29 December: 29.1 µg/m³, 1.3× usual Pátra, 30 December: 29.7 µg/m³, 1.3× usual Pátra, 31 December: 39.5 µg/m³, 1.8× usual Pátra, 1 January: 48.5 µg/m³, 2.2× usual Pátra, 2 January: no reading Pátra, 3 January: no reading Pátra, 4 January: no reading Pylaía Pylaía, 25 December: 9.8 µg/m³, 1.0× usual Pylaía, 26 December: 12.5 µg/m³, 1.2× usual Pylaía, 27 December: 12.0 µg/m³, 1.2× usual Pylaía, 28 December: 13.5 µg/m³, 1.3× usual Pylaía, 29 December: 17.9 µg/m³, 1.8× usual Pylaía, 30 December: 24.5 µg/m³, 2.4× usual Pylaía, 31 December: 20.0 µg/m³, 2.0× usual Pylaía, 1 January: 29.3 µg/m³, 2.9× usual Pylaía, 2 January: 19.4 µg/m³, 1.9× usual Pylaía, 3 January: 5.5 µg/m³, 0.5× usual Pylaía, 4 January: 3.8 µg/m³, 0.4× usual Sofia Sofia, 25 December: 10.9 µg/m³, 0.9× usual Sofia, 26 December: 14.4 µg/m³, 1.1× usual Sofia, 27 December: 7.5 µg/m³, 0.6× usual Sofia, 28 December: 18.6 µg/m³, 1.5× usual Sofia, 29 December: 20.7 µg/m³, 1.6× usual Sofia, 30 December: 15.8 µg/m³, 1.3× usual Sofia, 31 December: 14.3 µg/m³, 1.1× usual Sofia, 1 January: 27.7 µg/m³, 2.2× usual Sofia, 2 January: 8.9 µg/m³, 0.7× usual Sofia, 3 January: 11.5 µg/m³, 0.9× usual Sofia, 4 January: 7.2 µg/m³, 0.6× usual 25 Dec 27 29 31 1 Jan 2 4 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
Pristina Pristina, Kosovo 4 31 December 20.4 5.1× Iaşi Iași County, Romania 2 30 December 18.6 3.6× Bucharest Bucharest, Romania 2 1 January 18.6 3.3× Niš Central Serbia, Serbia 3 25 December 41.1 3.1× Athens Attica, Greece 3 1 January 19.9 3.0× Pylaía Central Macedonia, Greece 1 1 January 10.1 2.9× Piraeus Attica, Greece 1 25 December 14.0 2.8× Acharnés Attica, Greece 2 1 January 14.2 2.7× Veles Veles, North Macedonia 2 30 December 50.1 2.7× Ruse Ruse, Bulgaria 1 1 January 18.7 2.7× Haskovo Haskovo, Bulgaria 2 1 January 28.7 2.7× Trenčín Trenčín Region, Slovakia 2 30 December 14.4 2.6× Thessaloníki Central Macedonia, Greece 2 1 January 25.4 2.6× Nyíregyháza Szabolcs-Szatmár-Bereg, Hungary 1 29 December 21.5 2.6× Cluj-Napoca Cluj County, Romania 3 31 December 22.8 2.5× Snina Prešov Region, Slovakia 1 29 December 10.1 2.5× Volos Thessaly, Greece 2 1 January 28.0 2.5× Botevgrad Sofia, Bulgaria 2 30 December 23.0 2.5× Banja Luka Srpska, Bosnia and Herzegovina 2 28 December 55.8 2.4× Bratislava Bratislava Region, Slovakia 1 29 December 12.6 2.3× Traun Upper Austria, Austria 1 29 December 15.3 2.3× Zvolen Banská Bystrica Region, Slovakia 1 29 December 17.3 2.2× Handlová Trenčín Region, Slovakia 1 29 December 13.6 2.2× Partizánske Trenčín Region, Slovakia 2 29 December 16.0 2.2× Sofia Sofia-Capital, Bulgaria 1 1 January 12.6 2.2× Nitra Nitra Region, Slovakia 1 30 December 14.5 2.2× Skopje Grad Skopje, North Macedonia 3 1 January 50.3 2.2× Pátra West Greece, Greece 1 1 January 22.4 2.2× Žiar nad Hronom Banská Bystrica Region, Slovakia 1 29 December 14.7 2.2× Banská Bystrica Banská Bystrica Region, Slovakia 1 29 December 16.5 2.2× Trnava Trnava Region, Slovakia 1 29 December 16.3 2.1× Sarajevo Federation of B&H, Bosnia and Herzegovina 3 30 December 57.8 2.1× Szeged Csongrád, Hungary 2 29 December 14.8 2.1× Senica Trnava Region, Slovakia 1 29 December 13.5 2.0×
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 Slovakia and Greece
The largest of 8 episodes in Slovakia and Greece since our records began, by cities reached.
South-eastern Europe, December 2023 to January 2024 34 Eastern Europe, April 2026 24 Germany, Slovakia and 2 more countries, June 2023 19 Eastern Europe, July 2024 17 Slovakia, Czechia and Poland, June 2026 16 South-eastern Europe, December 2023 16 Eastern Europe, June 2026 14 Czechia and Slovakia, January 2023 9 Bars: cities reached; colour: the level of the episode's highest daily reading.
Use this page SmogRank, South-eastern Europe, December 2023 to January 2024: 34 cities with PM2.5 at twice their usual or more, 28 December 2023 to 1 January 2024, smogrank.com/episodes/2023-12-south-eastern-europe-2 (accessed 3 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.
