SmogRank / Episodes / Italy

Italy, Switzerland and France, January 2024

For 3 days, from 24 to 26 January 2024, 10 cities in Italy, Switzerland and France had PM2.5 at least twice their usual for the time of year. The worst reading was Capannori, Tuscany, Italy: 76.0 µg/m³ on 24 January, about 2.2× its usual 34.7. Ended 26 January.

No cause namedWe have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached10in 3 countries
Days324 to 26 January 2024
Worst day26 January7 cities counted
Furthest above usual3.9×Fréjus

Day by day

26 January 7 cities at twice their usual or more
Sannazzaro de' BurgondiMortaraPaviaVigevanoNovaraMilanCairo MontenotteLodiSaronnoMonzaVimercateTreviglioVareseComoMerateBraErbaDalmineLeccoLa SpeziaBergamoCremonaTurinBresciaMentonMonacoAostaContesPeschiera del GardaMantuaNiceBastiaCannesRoveretoPassySallanchesTrentoBernAlbertvillePayerneGapBorgo ValsuganaLaivesAnnecyBolzanoAnnemasseCrollesChambéryMeylanGrenobleManosqueBellegarde-sur-ValserineLa GardeToulonAix-en-ProvenceGardanneBesançonLons-le-SaunierMarseilleRomans-sur-IsèreVitrollesRognacBourg-en-BresseMarignaneJonageSalon-de-ProvenceValenceMeyzieuDoleAvignonFos-sur-MerGivorsFabrianoMâconVillefranche-sur-SaôneArlesSaint-ChamondChalon-sur-SaôneSaint-ÉtienneJesiChiaravalleNîmesFalconara MarittimaAnconaLunelMontceau-les-MinesPorto Potenza PicenaCivitanova MarcheMontpellierRijekaKlagenfurt am WörtherseeMoulinsNeversPesaroCapannoriAlessandriaCrescentinoLyonBorgomaneroLuganoBellinzonaGiubiascoFréjus
21 Jan2223242526272829
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

CapannoriCapannori, 21 January: 42.3 µg/m³Capannori, 22 January: 41.7 µg/m³Capannori, 23 January: 29.1 µg/m³Capannori, 24 January: 76.0 µg/m³, 2.2× its usual 34.7Capannori, 25 January: 52.8 µg/m³Capannori, 26 January: 39.9 µg/m³Capannori, 27 January: 50.6 µg/m³Capannori, 28 January: 40.4 µg/m³Capannori, 29 January: 54.4 µg/m³AlessandriaAlessandria, 21 January: 33.5 µg/m³Alessandria, 22 January: 40.7 µg/m³Alessandria, 23 January: 44.0 µg/m³Alessandria, 24 January: 58.9 µg/m³, 2.3× its usual 26.0Alessandria, 25 January: 67.0 µg/m³, 2.4× its usual 27.5Alessandria, 26 January: 55.6 µg/m³, 2.0× its usual 27.5Alessandria, 27 January: 37.9 µg/m³Alessandria, 28 January: 44.7 µg/m³Alessandria, 29 January: 18.3 µg/m³CrescentinoCrescentino, 21 January: 28.2 µg/m³Crescentino, 22 January: 37.3 µg/m³Crescentino, 23 January: 30.9 µg/m³Crescentino, 24 January: 54.9 µg/m³, 2.0× its usual 27.3Crescentino, 25 January: 64.1 µg/m³, 2.3× its usual 28.0Crescentino, 26 January: 69.1 µg/m³, 2.4× its usual 28.3Crescentino, 27 January: 39.7 µg/m³Crescentino, 28 January: 36.4 µg/m³Crescentino, 29 January: 36.0 µg/m³PesaroPesaro, 21 January: 15.1 µg/m³Pesaro, 22 January: 15.9 µg/m³Pesaro, 23 January: 28.6 µg/m³Pesaro, 24 January: 50.8 µg/m³, 2.1× its usual 24.3Pesaro, 25 January: no readingPesaro, 26 January: 85.9 µg/m³Pesaro, 27 January: 68.0 µg/m³Pesaro, 28 January: 29.9 µg/m³Pesaro, 29 January: 29.5 µg/m³FréjusFréjus, 21 January: 16.4 µg/m³Fréjus, 22 January: 8.0 µg/m³Fréjus, 23 January: 12.0 µg/m³Fréjus, 24 January: 29.7 µg/m³, 2.7× its usual 10.8Fréjus, 25 January: 45.9 µg/m³, 3.9× its usual 11.9Fréjus, 26 January: 40.1 µg/m³, 3.2× its usual 12.4Fréjus, 27 January: 22.9 µg/m³Fréjus, 28 January: 19.4 µg/m³Fréjus, 29 January: 20.7 µg/m³LyonLyon, 21 January: 26.1 µg/m³Lyon, 22 January: 13.0 µg/m³Lyon, 23 January: 26.2 µg/m³Lyon, 24 January: 28.0 µg/m³, 2.5× its usual 11.3Lyon, 25 January: 17.6 µg/m³Lyon, 26 January: 17.5 µg/m³Lyon, 27 January: 10.4 µg/m³Lyon, 28 January: 14.2 µg/m³Lyon, 29 January: 8.2 µg/m³BorgomaneroBorgomanero, 21 January: 18.4 µg/m³Borgomanero, 22 January: 22.8 µg/m³Borgomanero, 23 January: 24.0 µg/m³Borgomanero, 24 January: 40.3 µg/m³Borgomanero, 25 January: 57.2 µg/m³, 2.7× its usual 21.5Borgomanero, 26 January: 55.2 µg/m³, 2.5× its usual 22.0Borgomanero, 27 January: 28.0 µg/m³Borgomanero, 28 January: 30.7 µg/m³Borgomanero, 29 January: 25.0 µg/m³LuganoLugano, 21 January: 6.8 µg/m³Lugano, 22 January: 9.1 µg/m³Lugano, 23 January: 12.1 µg/m³Lugano, 24 January: 19.6 µg/m³Lugano, 25 January: 33.4 µg/m³, 3.4× its usual 9.9Lugano, 26 January: 36.2 µg/m³, 3.5× its usual 10.4Lugano, 27 January: 10.0 µg/m³Lugano, 28 January: 14.3 µg/m³Lugano, 29 January: 12.4 µg/m³GiubiascoGiubiasco, 21 January: 14.9 µg/m³Giubiasco, 22 January: 16.0 µg/m³Giubiasco, 23 January: 10.3 µg/m³Giubiasco, 24 January: 16.4 µg/m³Giubiasco, 25 January: 23.2 µg/m³Giubiasco, 26 January: 47.0 µg/m³, 3.6× its usual 12.9Giubiasco, 27 January: 8.1 µg/m³Giubiasco, 28 January: 20.5 µg/m³Giubiasco, 29 January: 14.7 µg/m³BellinzonaBellinzona, 21 January: 14.9 µg/m³Bellinzona, 22 January: 16.0 µg/m³Bellinzona, 23 January: 10.3 µg/m³Bellinzona, 24 January: 16.4 µg/m³Bellinzona, 25 January: 23.2 µg/m³Bellinzona, 26 January: 47.0 µg/m³, 3.6× its usual 12.9Bellinzona, 27 January: 8.1 µg/m³Bellinzona, 28 January: 20.5 µg/m³Bellinzona, 29 January: 14.7 µg/m³21 Jan2223242526272829
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
FréjusProvence-Alpes-Côte d'Azur, France3 45.925 January11.93.9×
GiubiascoTicino, Switzerland1 47.026 January12.93.6×
BellinzonaTicino, Switzerland1 47.026 January12.93.6×
LuganoTicino, Switzerland2 36.226 January10.43.5×
BorgomaneroPiedmont, Italy2 57.225 January21.52.7×
LyonAuvergne-Rhône-Alpes, France1 28.024 January11.32.5×
CrescentinoPiedmont, Italy3 69.126 January28.32.4×
AlessandriaPiedmont, Italy3 67.025 January27.52.4×
CapannoriTuscany, Italy1 76.024 January34.72.2×
PesaroThe Marches, Italy1 50.824 January24.32.1×

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 Italy and Switzerland

Number 5 of 9 episodes in Italy and Switzerland since our records began, by cities reached.

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

Use this page

SmogRank, Italy, Switzerland and France, January 2024: 10 cities with PM2.5 at twice their usual or more, 24 to 26 January 2024, smogrank.com/episodes/2024-01-italy-switzerland-and-france (accessed 5 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.