SmogRank / Episodes / Czechia

Czechia, Poland and Slovakia, January 2023

For 1 day, on 22 January 2023, 8 cities in Czechia, Poland and Slovakia had PM2.5 at least twice their usual for the time of year. The worst reading was Ostrava, Moravian-Silesian Region, Czechia: 48.0 µg/m³ on 22 January, about 3.0× its usual 15.9.

No cause namedWe have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached8in 3 countries
Days122 January 2023
Worst day22 January8 cities counted
Furthest above usual3.2×Třinec

Day by day

22 January 8 cities at twice their usual or more
Valašské MeziříčíHraniceHavířovBohumínZlínPúchovRacibórzPřerovKarvináWodzisław ŚląskiJastrzębie ZdrójTrenčínKroměřížOlomoucČadcaKędzierzyn-KoźleŽilinaPrievidzaPartizánskeMartinCzechowice-DziedziceBielsko-BialaOpoleHandlováNysaHodonínKatowiceNitraTrnavaŽiar nad HronomSereďRužomberokBanská BystricaŽideniceBrnoPezinokSenecZvolenMalackyKłodzkoLiptovský MikulášBratislavaDevínska Nová VesKomárnoWrocławEsztergomGyőrKrakówRadomskoLučenecŽďár nad SázavouZnojmoKlosterneuburgViennaKaliszHradec KrálovéPerchtoldsdorfMödlingPardubiceŁaskPopradBadenJihlavaSpišská Nová VesŁódźJelenia GóraZgierzSankt PöltenKielceKazincbarcikaTarnówLiberecMladá BoleslavBardejovPrešovBogatyniaKošiceStarachowiceDębicaZielona GóraJasłoAmstettenMielecŻaryČeské BudějoviceRadomPragueVranov nad TopľouKrosnoTrebišovSteyrLinzHumennéKladnoBerounAnsfeldenDěčínRzeszówÚstí nad LabemSninaNiskoWelsCottbusTepliceMostLitvínovPilsenLubnjowPassauLublinŁukówKrapkowiceFrýdek-MístekSenicaCieszynČeský TěšínOpavaOstravaTřinec
19 Jan202122232425
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

OstravaOstrava, 19 January: 21.9 µg/m³Ostrava, 20 January: 38.0 µg/m³Ostrava, 21 January: 26.0 µg/m³Ostrava, 22 January: 48.0 µg/m³, 3.0× its usual 15.9Ostrava, 23 January: 25.3 µg/m³Ostrava, 24 January: 20.1 µg/m³Ostrava, 25 January: 11.0 µg/m³TřinecTřinec, 19 January: no readingTřinec, 20 January: no readingTřinec, 21 January: no readingTřinec, 22 January: 43.0 µg/m³, 3.2× its usual 13.3Třinec, 23 January: no readingTřinec, 24 January: no readingTřinec, 25 January: no readingČeský TěšínČeský Těšín, 19 January: 25.4 µg/m³Český Těšín, 20 January: 39.1 µg/m³Český Těšín, 21 January: 30.6 µg/m³Český Těšín, 22 January: 41.1 µg/m³, 2.5× its usual 16.5Český Těšín, 23 January: 23.8 µg/m³Český Těšín, 24 January: 22.5 µg/m³Český Těšín, 25 January: 12.6 µg/m³CieszynCieszyn, 19 January: 25.4 µg/m³Cieszyn, 20 January: 39.1 µg/m³Cieszyn, 21 January: 30.6 µg/m³Cieszyn, 22 January: 41.1 µg/m³, 2.5× its usual 16.5Cieszyn, 23 January: 23.8 µg/m³Cieszyn, 24 January: 22.5 µg/m³Cieszyn, 25 January: 12.6 µg/m³OpavaOpava, 19 January: no readingOpava, 20 January: no readingOpava, 21 January: no readingOpava, 22 January: 39.2 µg/m³, 2.9× its usual 13.7Opava, 23 January: no readingOpava, 24 January: no readingOpava, 25 January: no readingFrýdek-MístekFrýdek-Místek, 19 January: 24.0 µg/m³Frýdek-Místek, 20 January: 34.2 µg/m³Frýdek-Místek, 21 January: 26.7 µg/m³Frýdek-Místek, 22 January: 35.3 µg/m³, 2.3× its usual 15.6Frýdek-Místek, 23 January: 21.6 µg/m³Frýdek-Místek, 24 January: 18.8 µg/m³Frýdek-Místek, 25 January: 11.6 µg/m³SenicaSenica, 19 January: 17.2 µg/m³Senica, 20 January: 21.9 µg/m³Senica, 21 January: 10.8 µg/m³Senica, 22 January: 31.2 µg/m³, 2.4× its usual 13.2Senica, 23 January: 18.2 µg/m³Senica, 24 January: 19.7 µg/m³Senica, 25 January: 19.1 µg/m³KrapkowiceKrapkowice, 19 January: 23.9 µg/m³Krapkowice, 20 January: 44.2 µg/m³Krapkowice, 21 January: 23.5 µg/m³Krapkowice, 22 January: 30.9 µg/m³, 2.1× its usual 15.0Krapkowice, 23 January: 24.5 µg/m³Krapkowice, 24 January: 20.7 µg/m³Krapkowice, 25 January: 34.3 µg/m³19 Jan202122232425
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.
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

Every city it reached

CityDaysHighestUsualAbove usual
TřinecMoravian-Silesian Region, Czechia1 43.022 January13.33.2×
OstravaMoravian-Silesian Region, Czechia1 48.022 January15.93.0×
OpavaMoravian-Silesian Region, Czechia1 39.222 January13.72.9×
Český TěšínMoravian-Silesian Region, Czechia1 41.122 January16.52.5×
CieszynSilesia, Poland1 41.122 January16.52.5×
SenicaTrnava Region, Slovakia1 31.222 January13.22.4×
Frýdek-MístekMoravian-Silesian Region, Czechia1 35.322 January15.62.3×
KrapkowiceOpole Voivodeship, Poland1 30.922 January15.02.1×

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 Czechia and Poland

Number 43 of 43 episodes in Czechia and Poland since our records began, by cities reached.

Bars: cities reached; colour: the level of the episode's highest daily reading. All 43.

Use this page

SmogRank, Czechia, Poland and Slovakia, January 2023: 8 cities with PM2.5 at twice their usual or more, 22 January 2023, smogrank.com/episodes/2023-01-czechia-poland-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.