SmogRank / Episodes / Poland
Poland, Czechia and Slovakia, April 2026
For 3 days, from 10 to 12 April 2026, 32 cities in Poland, Czechia and Slovakia had PM2.5 at least twice their usual for the time of year. The worst reading was Radomsko, Łódź Voivodeship, Poland: 60.2 µg/m³ on 11 April, about 4.2× its usual 14.2.
No cause named We have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached 32 in 3 countries
Days 3 10 to 12 April 2026
Worst day 11 April 27 cities counted
Furthest above usual 4.2× Radomsko
Day by day
Play 11 April 27 cities at twice their usual or more
Łódź Katowice Włocławek Bielsko-Biala Płock Kraków Žilina Żyrardów Púchov Kielce Martin Ružomberok Trenčín Liptovský Mikuláš Pruszków Ciechanów Warsaw Konstancin-Jeziorna Židenice Hodonín Jelenia Góra Brno Wawer Poprad Hradec Králové Pardubice Jasło Bardejov Znojmo Prešov Nisko Eisenhüttenstadt Vranov nad Topľou Lublin Frankfurt (Oder) Humenné Cottbus Prague Snina Szczecin Przemyśl Schwedt (Oder) Lubnjow České Budějovice Zamość Strausberg Neuenhagen Königs Wusterhausen Białystok Bernau bei Berlin Blankenfelde-Mahlow Berlin Teltow Luckenwalde Kleinmachnow Oranienburg Potsdam Falkensee Neubrandenburg Nauen Wittenberg Neuruppin Brandenburg an der Havel Altenburg Bitterfeld-Wolfen Dessau Greiz Zeitz Gera Merseburg Halle (Saale) Marktredwitz Weiden Schwandorf in Bayern Legionowo Radom Toruń Čadca Bydgoszcz Jarosław Starachowice Łask Poznań Racibórz Żywiec Jastrzębie Zdrój Wrocław Zielona Góra Rzeszów Dębica Zgierz Opole Kędzierzyn-Koźle Mielec Krosno Czechowice-Dziedzice Gorzów Wielkopolski Stodůlky Kalisz Tarnów Kłodzko Żary Otwock Říčany Brzeg Radomsko 7 Apr 8 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
Jastrzębie Zdrój Jastrzębie Zdrój, 7 April: 8.3 µg/m³ Jastrzębie Zdrój, 8 April: 11.7 µg/m³ Jastrzębie Zdrój, 9 April: no reading Jastrzębie Zdrój, 10 April: 42.9 µg/m³, 2.3× its usual 18.3 Jastrzębie Zdrój, 11 April: 39.9 µg/m³, 2.2× its usual 18.0 Jastrzębie Zdrój, 12 April: 35.3 µg/m³ Jastrzębie Zdrój, 13 April: 15.7 µg/m³ Jastrzębie Zdrój, 14 April: no reading Jastrzębie Zdrój, 15 April: no reading Czechowice-Dziedzice Czechowice-Dziedzice, 7 April: 6.0 µg/m³ Czechowice-Dziedzice, 8 April: 11.0 µg/m³ Czechowice-Dziedzice, 9 April: no reading Czechowice-Dziedzice, 10 April: 42.8 µg/m³, 2.9× its usual 15.0 Czechowice-Dziedzice, 11 April: 39.2 µg/m³, 2.7× its usual 14.5 Czechowice-Dziedzice, 12 April: 31.9 µg/m³, 2.2× its usual 14.2 Czechowice-Dziedzice, 13 April: 11.2 µg/m³ Czechowice-Dziedzice, 14 April: no reading Czechowice-Dziedzice, 15 April: no reading Tarnów Tarnów, 7 April: 5.4 µg/m³ Tarnów, 8 April: 5.2 µg/m³ Tarnów, 9 April: 13.1 µg/m³ Tarnów, 10 April: 30.7 µg/m³, 2.6× its usual 11.8 Tarnów, 11 April: 37.8 µg/m³, 3.2× its usual 11.8 Tarnów, 12 April: 33.1 µg/m³, 2.9× its usual 11.6 Tarnów, 13 April: 11.8 µg/m³ Tarnów, 14 April: no reading Tarnów, 15 April: no reading Brzeg Brzeg, 7 April: 5.1 µg/m³ Brzeg, 8 April: 7.8 µg/m³ Brzeg, 9 April: no reading Brzeg, 10 April: 28.7 µg/m³, 3.0× its usual 9.7 Brzeg, 11 April: 30.4 µg/m³, 3.2× its usual 9.6 Brzeg, 12 April: 37.8 µg/m³, 3.9× its usual 9.6 Brzeg, 13 April: 14.4 µg/m³ Brzeg, 14 April: no reading Brzeg, 15 April: no reading Opole Opole, 7 April: 4.2 µg/m³ Opole, 8 April: 5.7 µg/m³ Opole, 9 April: 13.9 µg/m³ Opole, 10 April: 27.7 µg/m³, 2.3× its usual 11.8 Opole, 11 April: 28.3 µg/m³, 2.4× its usual 11.8 Opole, 12 April: 29.5 µg/m³, 2.6× its usual 11.4 Opole, 13 April: 9.1 µg/m³ Opole, 14 April: no reading Opole, 15 April: no reading Říčany Říčany, 7 April: 1.0 µg/m³ Říčany, 8 April: 5.7 µg/m³ Říčany, 9 April: 8.2 µg/m³ Říčany, 10 April: 26.7 µg/m³, 2.2× its usual 12.0 Říčany, 11 April: 36.2 µg/m³, 3.0× its usual 12.0 Říčany, 12 April: 42.4 µg/m³, 3.6× its usual 11.7 Říčany, 13 April: 25.4 µg/m³ Říčany, 14 April: 25.4 µg/m³ Říčany, 15 April: 36.8 µg/m³ Kędzierzyn-Koźle Kędzierzyn-Koźle, 7 April: 5.0 µg/m³ Kędzierzyn-Koźle, 8 April: 6.7 µg/m³ Kędzierzyn-Koźle, 9 April: no reading Kędzierzyn-Koźle, 10 April: 26.4 µg/m³, 2.2× its usual 11.9 Kędzierzyn-Koźle, 11 April: 30.6 µg/m³, 2.6× its usual 11.7 Kędzierzyn-Koźle, 12 April: 29.6 µg/m³, 2.5× its usual 11.7 Kędzierzyn-Koźle, 13 April: 9.6 µg/m³ Kędzierzyn-Koźle, 14 April: no reading Kędzierzyn-Koźle, 15 April: no reading Radomsko Radomsko, 7 April: 8.6 µg/m³ Radomsko, 8 April: 15.6 µg/m³ Radomsko, 9 April: no reading Radomsko, 10 April: 26.4 µg/m³ Radomsko, 11 April: 60.2 µg/m³, 4.2× its usual 14.2 Radomsko, 12 April: 45.6 µg/m³, 3.3× its usual 13.9 Radomsko, 13 April: 9.8 µg/m³ Radomsko, 14 April: no reading Radomsko, 15 April: no reading Otwock Otwock, 7 April: 8.9 µg/m³ Otwock, 8 April: 10.5 µg/m³ Otwock, 9 April: no reading Otwock, 10 April: 26.4 µg/m³ Otwock, 11 April: 52.9 µg/m³, 3.5× its usual 15.1 Otwock, 12 April: 48.4 µg/m³, 3.3× its usual 14.8 Otwock, 13 April: 11.4 µg/m³ Otwock, 14 April: no reading Otwock, 15 April: no reading Kalisz Kalisz, 7 April: 10.2 µg/m³ Kalisz, 8 April: 12.9 µg/m³ Kalisz, 9 April: no reading Kalisz, 10 April: 29.2 µg/m³ Kalisz, 11 April: 47.8 µg/m³, 3.0× its usual 15.7 Kalisz, 12 April: 34.7 µg/m³, 2.3× its usual 15.4 Kalisz, 13 April: 20.4 µg/m³ Kalisz, 14 April: no reading Kalisz, 15 April: no reading Żywiec Żywiec, 7 April: 12.9 µg/m³ Żywiec, 8 April: 16.4 µg/m³ Żywiec, 9 April: no reading Żywiec, 10 April: 37.5 µg/m³ Żywiec, 11 April: 37.5 µg/m³, 2.3× its usual 16.6 Żywiec, 12 April: 35.7 µg/m³, 2.2× its usual 16.1 Żywiec, 13 April: 20.8 µg/m³ Żywiec, 14 April: no reading Żywiec, 15 April: no reading Łask Łask, 7 April: 10.6 µg/m³ Łask, 8 April: 11.9 µg/m³ Łask, 9 April: no reading Łask, 10 April: 18.5 µg/m³ Łask, 11 April: 36.2 µg/m³, 2.2× its usual 16.7 Łask, 12 April: 29.3 µg/m³ Łask, 13 April: 13.1 µg/m³ Łask, 14 April: no reading Łask, 15 April: no reading Zgierz Zgierz, 7 April: 11.0 µg/m³ Zgierz, 8 April: 12.8 µg/m³ Zgierz, 9 April: 10.3 µg/m³ Zgierz, 10 April: 18.5 µg/m³ Zgierz, 11 April: 35.6 µg/m³, 2.5× its usual 14.3 Zgierz, 12 April: 24.6 µg/m³ Zgierz, 13 April: 7.6 µg/m³ Zgierz, 14 April: no reading Zgierz, 15 April: no reading Dębica Dębica, 7 April: 5.6 µg/m³ Dębica, 8 April: 6.8 µg/m³ Dębica, 9 April: 12.1 µg/m³ Dębica, 10 April: 26.6 µg/m³ Dębica, 11 April: 33.8 µg/m³, 2.5× its usual 13.7 Dębica, 12 April: 25.7 µg/m³ Dębica, 13 April: 12.8 µg/m³ Dębica, 14 April: no reading Dębica, 15 April: no reading Stodůlky Stodůlky, 7 April: 1.4 µg/m³ Stodůlky, 8 April: 4.1 µg/m³ Stodůlky, 9 April: 7.7 µg/m³ Stodůlky, 10 April: 28.5 µg/m³ Stodůlky, 11 April: 32.7 µg/m³, 2.2× its usual 14.8 Stodůlky, 12 April: 41.1 µg/m³, 3.0× its usual 13.9 Stodůlky, 13 April: 24.7 µg/m³ Stodůlky, 14 April: 29.6 µg/m³ Stodůlky, 15 April: 37.3 µg/m³ Mielec Mielec, 7 April: 5.3 µg/m³ Mielec, 8 April: 6.3 µg/m³ Mielec, 9 April: 11.4 µg/m³ Mielec, 10 April: 24.0 µg/m³ Mielec, 11 April: 32.4 µg/m³, 2.6× its usual 12.4 Mielec, 12 April: 29.3 µg/m³, 2.4× its usual 12.2 Mielec, 13 April: 7.1 µg/m³ Mielec, 14 April: no reading Mielec, 15 April: no reading Poznań Poznań, 7 April: 6.5 µg/m³ Poznań, 8 April: 5.6 µg/m³ Poznań, 9 April: no reading Poznań, 10 April: 17.4 µg/m³ Poznań, 11 April: 31.5 µg/m³, 2.3× its usual 13.8 Poznań, 12 April: 28.5 µg/m³, 2.1× its usual 13.5 Poznań, 13 April: 15.1 µg/m³ Poznań, 14 April: no reading Poznań, 15 April: no reading Rzeszów Rzeszów, 7 April: 7.3 µg/m³ Rzeszów, 8 April: 6.6 µg/m³ Rzeszów, 9 April: no reading Rzeszów, 10 April: 20.5 µg/m³ Rzeszów, 11 April: 30.4 µg/m³, 2.5× its usual 12.4 Rzeszów, 12 April: 25.8 µg/m³, 2.1× its usual 12.2 Rzeszów, 13 April: 11.7 µg/m³ Rzeszów, 14 April: no reading Rzeszów, 15 April: no reading Toruń Toruń, 7 April: 7.6 µg/m³ Toruń, 8 April: 9.3 µg/m³ Toruń, 9 April: 8.8 µg/m³ Toruń, 10 April: 15.8 µg/m³ Toruń, 11 April: 30.3 µg/m³, 2.1× its usual 14.4 Toruń, 12 April: 18.0 µg/m³ Toruń, 13 April: 12.1 µg/m³ Toruń, 14 April: no reading Toruń, 15 April: no reading Gorzów Wielkopolski Gorzów Wielkopolski, 7 April: 7.5 µg/m³ Gorzów Wielkopolski, 8 April: 14.8 µg/m³ Gorzów Wielkopolski, 9 April: 9.2 µg/m³ Gorzów Wielkopolski, 10 April: 13.8 µg/m³ Gorzów Wielkopolski, 11 April: 30.2 µg/m³, 3.0× its usual 10.1 Gorzów Wielkopolski, 12 April: 28.1 µg/m³, 2.8× its usual 9.9 Gorzów Wielkopolski, 13 April: 20.1 µg/m³ Gorzów Wielkopolski, 14 April: no reading Gorzów Wielkopolski, 15 April: no reading Radom Radom, 7 April: 7.7 µg/m³ Radom, 8 April: 8.7 µg/m³ Radom, 9 April: 10.3 µg/m³ Radom, 10 April: 17.0 µg/m³ Radom, 11 April: 29.9 µg/m³, 2.1× its usual 14.3 Radom, 12 April: 22.1 µg/m³ Radom, 13 April: 9.8 µg/m³ Radom, 14 April: no reading Radom, 15 April: no reading Starachowice Starachowice, 7 April: 8.6 µg/m³ Starachowice, 8 April: 9.6 µg/m³ Starachowice, 9 April: no reading Starachowice, 10 April: 15.5 µg/m³ Starachowice, 11 April: 29.4 µg/m³, 2.2× its usual 13.6 Starachowice, 12 April: 23.8 µg/m³ Starachowice, 13 April: 10.8 µg/m³ Starachowice, 14 April: no reading Starachowice, 15 April: no reading Krosno Krosno, 7 April: 5.9 µg/m³ Krosno, 8 April: 11.9 µg/m³ Krosno, 9 April: no reading Krosno, 10 April: 21.8 µg/m³ Krosno, 11 April: 28.3 µg/m³, 2.7× its usual 10.3 Krosno, 12 April: 17.5 µg/m³ Krosno, 13 April: 8.8 µg/m³ Krosno, 14 April: no reading Krosno, 15 April: no reading Jarosław Jarosław, 7 April: 5.1 µg/m³ Jarosław, 8 April: 6.1 µg/m³ Jarosław, 9 April: no reading Jarosław, 10 April: 15.2 µg/m³ Jarosław, 11 April: 27.9 µg/m³, 2.2× its usual 12.8 Jarosław, 12 April: 15.3 µg/m³ Jarosław, 13 April: 6.7 µg/m³ Jarosław, 14 April: no reading Jarosław, 15 April: no reading Kłodzko Kłodzko, 7 April: 11.3 µg/m³ Kłodzko, 8 April: 11.0 µg/m³ Kłodzko, 9 April: no reading Kłodzko, 10 April: 25.7 µg/m³ Kłodzko, 11 April: 26.6 µg/m³, 2.0× its usual 13.3 Kłodzko, 12 April: 42.8 µg/m³, 3.3× its usual 13.0 Kłodzko, 13 April: 29.6 µg/m³ Kłodzko, 14 April: no reading Kłodzko, 15 April: no reading Bydgoszcz Bydgoszcz, 7 April: 3.7 µg/m³ Bydgoszcz, 8 April: 3.5 µg/m³ Bydgoszcz, 9 April: 5.9 µg/m³ Bydgoszcz, 10 April: 9.1 µg/m³ Bydgoszcz, 11 April: 26.2 µg/m³, 2.2× its usual 11.8 Bydgoszcz, 12 April: 12.9 µg/m³ Bydgoszcz, 13 April: 10.3 µg/m³ Bydgoszcz, 14 April: no reading Bydgoszcz, 15 April: no reading Čadca Čadca, 7 April: no reading Čadca, 8 April: 9.6 µg/m³ Čadca, 9 April: no reading Čadca, 10 April: 17.8 µg/m³ Čadca, 11 April: 25.2 µg/m³, 2.2× its usual 11.3 Čadca, 12 April: 19.2 µg/m³ Čadca, 13 April: 10.4 µg/m³ Čadca, 14 April: 13.0 µg/m³ Čadca, 15 April: no reading Racibórz Racibórz, 7 April: 5.4 µg/m³ Racibórz, 8 April: 7.8 µg/m³ Racibórz, 9 April: no reading Racibórz, 10 April: 26.0 µg/m³ Racibórz, 11 April: 28.4 µg/m³ Racibórz, 12 April: 31.7 µg/m³, 2.3× its usual 14.0 Racibórz, 13 April: 11.7 µg/m³ Racibórz, 14 April: no reading Racibórz, 15 April: no reading Wrocław Wrocław, 7 April: 10.1 µg/m³ Wrocław, 8 April: 10.3 µg/m³ Wrocław, 9 April: 15.7 µg/m³ Wrocław, 10 April: 25.0 µg/m³ Wrocław, 11 April: 25.2 µg/m³ Wrocław, 12 April: 31.6 µg/m³, 2.4× its usual 13.1 Wrocław, 13 April: 16.0 µg/m³ Wrocław, 14 April: no reading Wrocław, 15 April: no reading Żary Żary, 7 April: 5.2 µg/m³ Żary, 8 April: 9.3 µg/m³ Żary, 9 April: 12.1 µg/m³ Żary, 10 April: 19.8 µg/m³ Żary, 11 April: 19.5 µg/m³ Żary, 12 April: 30.2 µg/m³, 3.5× its usual 8.7 Żary, 13 April: 21.8 µg/m³ Żary, 14 April: no reading Żary, 15 April: no reading Zielona Góra Zielona Góra, 7 April: 5.7 µg/m³ Zielona Góra, 8 April: 6.4 µg/m³ Zielona Góra, 9 April: 9.4 µg/m³ Zielona Góra, 10 April: 13.9 µg/m³ Zielona Góra, 11 April: 16.4 µg/m³ Zielona Góra, 12 April: 26.3 µg/m³, 2.5× its usual 10.6 Zielona Góra, 13 April: 14.9 µg/m³ Zielona Góra, 14 April: no reading Zielona Góra, 15 April: no reading Legionowo Legionowo, 7 April: 5.7 µg/m³ Legionowo, 8 April: 6.0 µg/m³ Legionowo, 9 April: 7.9 µg/m³ Legionowo, 10 April: 16.4 µg/m³ Legionowo, 11 April: 20.2 µg/m³ Legionowo, 12 April: 25.8 µg/m³, 2.0× its usual 12.7 Legionowo, 13 April: 10.1 µg/m³ Legionowo, 14 April: no reading Legionowo, 15 April: no reading 7 Apr 8 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
Radomsko Łódź Voivodeship, Poland 2 11 April 14.2 4.2× Brzeg Opole Voivodeship, Poland 3 12 April 9.6 3.9× Říčany Central Bohemia, Czechia 3 12 April 11.7 3.6× Otwock Mazovia, Poland 2 11 April 15.1 3.5× Żary Lubusz, Poland 1 12 April 8.7 3.5× Kłodzko Lower Silesia, Poland 2 12 April 13.0 3.3× Tarnów Lesser Poland, Poland 3 11 April 11.8 3.2× Kalisz Greater Poland, Poland 2 11 April 15.7 3.0× Stodůlky Prague, Czechia 2 12 April 13.9 3.0× Gorzów Wielkopolski Lubusz, Poland 2 11 April 10.1 3.0× Czechowice-Dziedzice Silesia, Poland 3 10 April 15.0 2.9× Krosno Subcarpathia, Poland 1 11 April 10.3 2.7× Mielec Subcarpathia, Poland 2 11 April 12.4 2.6× Kędzierzyn-Koźle Opole Voivodeship, Poland 3 11 April 11.7 2.6× Opole Opole Voivodeship, Poland 3 12 April 11.4 2.6× Zgierz Łódź Voivodeship, Poland 1 11 April 14.3 2.5× Dębica Subcarpathia, Poland 1 11 April 13.7 2.5× Rzeszów Subcarpathia, Poland 2 11 April 12.4 2.5× Zielona Góra Lubusz, Poland 1 12 April 10.6 2.5× Wrocław Lower Silesia, Poland 1 12 April 13.1 2.4× Jastrzębie Zdrój Silesia, Poland 2 10 April 18.3 2.3× Żywiec Silesia, Poland 2 11 April 16.6 2.3× Racibórz Silesia, Poland 1 12 April 14.0 2.3× Poznań Greater Poland, Poland 2 11 April 13.8 2.3× Łask Łódź Voivodeship, Poland 1 11 April 16.7 2.2× Starachowice Świętokrzyskie, Poland 1 11 April 13.6 2.2× Jarosław Subcarpathia, Poland 1 11 April 12.8 2.2× Bydgoszcz Kujawsko-Pomorskie, Poland 1 11 April 11.8 2.2× Čadca Žilina Region, Slovakia 1 11 April 11.3 2.2× Toruń Kujawsko-Pomorskie, Poland 1 11 April 14.4 2.1× Radom Mazovia, Poland 1 11 April 14.3 2.1× Legionowo Mazovia, Poland 1 12 April 12.7 2.0×
Daily means in µg/m³, over the days each city counted in this episode. Highest: its highest of those days. Usual: the city's median for the time of year of that day (its days within 21 days of the date, every year, leaving out the week around it). Above usual: its highest day against that, with a usual under 5 µg/m³ taken as 5.
Against other episodes in Poland and Czechia
Number 17 of 43 episodes in Poland and Czechia since our records began, by cities reached.
Eastern Europe, October and November 2024 141 Europe, 22 to 23 January 2025 123 Eastern Europe, December 2025 118 Eastern Europe, 4 to 9 December 2023 110 Europe, 8 to 10 November 2025 73 Eastern Europe, January 2026 70 Eastern Europe, March 2023 59 Germany, Poland and Czechia, February 2026 54 North-eastern Europe, December 2025 54 Eastern Europe, 30 November to 8 December 2024 53 Eastern Europe, September 2023 53 Poland, September 2024 51 Poland, Czechia and Slovakia, April 2026 32 Bars: cities reached; colour: the level of the episode's highest daily reading. All 43 .
Use this page SmogRank, Poland, Czechia and Slovakia, April 2026: 32 cities with PM2.5 at twice their usual or more, 10 to 12 April 2026, smogrank.com/episodes/2026-04-poland-czechia-and-slovakia (accessed 4 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.
