SmogRank / Episodes / Italy

Italy, France and Switzerland, January 2024

For 3 days, from 24 to 26 January 2024, 8 cities in Italy, France and Switzerland 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.

No cause namedWe have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached8in 3 countries
Days324 to 26 January 2024
Worst day24 January5 cities counted
Furthest above usual3.9×Fréjus

Day by day

24 January 5 cities at twice their usual or more
PaviaVigevanoNovaraMilanLodiSaronnoMonzaVimercateTreviglioVareseComoBraErbaDalmineLeccoLa SpeziaBergamoCremonaTurinBresciaMentonMonacoAostaMantuaNiceBastiaCannesRoveretoSallanchesTrentoBernAlbertvilleGapAnnecyBolzanoAnnemasseChambéryMeylanGrenobleManosqueLa GardeToulonAix-en-ProvenceGardanneBesançonLons-le-SaunierMarseilleRomans-sur-IsèreVitrollesBourg-en-BresseMarignaneSalon-de-ProvenceValenceMeyzieuDoleAvignonFos-sur-MerGivorsFabrianoMâconVillefranche-sur-SaôneArlesSaint-ChamondChalon-sur-SaôneSaint-ÉtienneJesiNîmesFalconara MarittimaAnconaLunelMontceau-les-MinesCivitanova MarcheMontpellierRijekaKlagenfurt am WörtherseeMoulinsNeversPesaroCapannoriAlessandriaLyonBorgomaneroLuganoBellinzonaFréjus
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

LyonLyon, 21 January: 26.1 µg/m³, 2.3× usualLyon, 22 January: 13.0 µg/m³, 1.2× usualLyon, 23 January: 26.2 µg/m³, 2.3× usualLyon, 24 January: 28.0 µg/m³, 2.5× usualLyon, 25 January: 17.6 µg/m³, 1.6× usualLyon, 26 January: 17.5 µg/m³, 1.5× usualLyon, 27 January: 10.4 µg/m³, 0.9× usualLyon, 28 January: 14.2 µg/m³, 1.3× usualLyon, 29 January: 8.2 µg/m³, 0.7× usualCapannoriCapannori, 21 January: 42.3 µg/m³, 1.2× usualCapannori, 22 January: 41.7 µg/m³, 1.2× usualCapannori, 23 January: 29.1 µg/m³, 0.8× usualCapannori, 24 January: 76.0 µg/m³, 2.2× usualCapannori, 25 January: 52.8 µg/m³, 1.5× usualCapannori, 26 January: 39.9 µg/m³, 1.1× usualCapannori, 27 January: 50.6 µg/m³, 1.5× usualCapannori, 28 January: 40.4 µg/m³, 1.2× usualCapannori, 29 January: 54.4 µg/m³, 1.6× usualAlessandriaAlessandria, 21 January: 33.5 µg/m³, 1.2× usualAlessandria, 22 January: 40.7 µg/m³, 1.5× usualAlessandria, 23 January: 44.0 µg/m³, 1.6× usualAlessandria, 24 January: 58.9 µg/m³, 2.1× usualAlessandria, 25 January: 67.0 µg/m³, 2.4× usualAlessandria, 26 January: 55.6 µg/m³, 2.0× usualAlessandria, 27 January: 37.9 µg/m³, 1.4× usualAlessandria, 28 January: 44.7 µg/m³, 1.6× usualAlessandria, 29 January: 18.3 µg/m³, 0.7× usualPesaroPesaro, 21 January: 15.1 µg/m³, 0.6× usualPesaro, 22 January: 15.9 µg/m³, 0.7× usualPesaro, 23 January: 28.6 µg/m³, 1.2× usualPesaro, 24 January: 50.8 µg/m³, 2.1× usualPesaro, 25 January: no readingPesaro, 26 January: 85.9 µg/m³, 3.5× usualPesaro, 27 January: 68.0 µg/m³, 2.8× usualPesaro, 28 January: 29.9 µg/m³, 1.2× usualPesaro, 29 January: 29.5 µg/m³, 1.2× usualFréjusFréjus, 21 January: 16.4 µg/m³, 1.4× usualFréjus, 22 January: 8.0 µg/m³, 0.7× usualFréjus, 23 January: 12.0 µg/m³, 1.0× usualFréjus, 24 January: 29.7 µg/m³, 2.5× usualFréjus, 25 January: 45.9 µg/m³, 3.9× usualFréjus, 26 January: 40.1 µg/m³, 3.4× usualFréjus, 27 January: 22.9 µg/m³, 1.9× usualFréjus, 28 January: 19.4 µg/m³, 1.6× usualFréjus, 29 January: 20.7 µg/m³, 1.7× usualBorgomaneroBorgomanero, 21 January: 18.4 µg/m³, 0.9× usualBorgomanero, 22 January: 22.8 µg/m³, 1.1× usualBorgomanero, 23 January: 24.0 µg/m³, 1.1× usualBorgomanero, 24 January: 40.3 µg/m³, 1.9× usualBorgomanero, 25 January: 57.2 µg/m³, 2.7× usualBorgomanero, 26 January: 55.2 µg/m³, 2.6× usualBorgomanero, 27 January: 28.0 µg/m³, 1.3× usualBorgomanero, 28 January: 30.7 µg/m³, 1.4× usualBorgomanero, 29 January: 25.0 µg/m³, 1.2× usualLuganoLugano, 21 January: 6.8 µg/m³, 0.7× usualLugano, 22 January: 9.1 µg/m³, 0.9× usualLugano, 23 January: 12.1 µg/m³, 1.2× usualLugano, 24 January: 19.6 µg/m³, 1.9× usualLugano, 25 January: 33.4 µg/m³, 3.2× usualLugano, 26 January: 36.2 µg/m³, 3.5× usualLugano, 27 January: 10.0 µg/m³, 1.0× usualLugano, 28 January: 14.3 µg/m³, 1.4× usualLugano, 29 January: 12.4 µg/m³, 1.2× usualBellinzonaBellinzona, 21 January: 14.9 µg/m³, 1.2× usualBellinzona, 22 January: 16.0 µg/m³, 1.2× usualBellinzona, 23 January: 10.3 µg/m³, 0.8× usualBellinzona, 24 January: 16.4 µg/m³, 1.3× usualBellinzona, 25 January: 23.2 µg/m³, 1.8× usualBellinzona, 26 January: 47.0 µg/m³, 3.6× usualBellinzona, 27 January: 8.1 µg/m³, 0.6× usualBellinzona, 28 January: 20.5 µg/m³, 1.6× usualBellinzona, 29 January: 14.7 µg/m³, 1.1× usual21 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×
BellinzonaTicino, Switzerland1 47.026 January12.93.6×
PesaroThe Marches, Italy1 85.926 January24.33.5×
LuganoTicino, Switzerland2 36.226 January10.43.5×
BorgomaneroPiedmont, Italy2 57.225 January21.52.7×
LyonAuvergne-Rhône-Alpes, France1 28.024 January11.32.5×
AlessandriaPiedmont, Italy3 67.025 January27.52.4×
CapannoriTuscany, Italy1 76.024 January34.72.2×

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 Italy and France

Number 28 of 30 episodes in Italy and France since our records began, by cities reached.

Bars: cities reached; colour: the level of the episode's highest daily reading. All 30.

Use this page

SmogRank, Italy, France and Switzerland, January 2024: 8 cities with PM2.5 at twice their usual or more, 24 to 26 January 2024, smogrank.com/episodes/2024-01-italy-france-and-switzerland (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.