SmogRank / Episodes / France

Auvergne-Rhône-Alpes and Provence-Alpes-Côte d'Azur, France, January 2023

For 1 day, on 30 January 2023, 8 cities in France had PM2.5 at least twice their usual for the time of year. The worst reading was Crolles, Auvergne-Rhône-Alpes, France: 31.6 µg/m³ on 30 January, about 2.2× its usual 14.4. Ended 30 January.

No cause namedWe have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached8in 1 country
Days130 January 2023
Worst day30 January8 cities counted
Furthest above usual2.3×Annemasse

Day by day

30 January 8 cities at twice their usual or more
GapPassySallanchesAnnecyAostaTurinBellegarde-sur-ValserineRomans-sur-IsèreNiceCannesMonacoMentonCrescentinoFréjusValenceJonageMeyzieuBourg-en-BresseAix-en-ProvenceLyonGivorsCairo MontenotteGardanneLons-le-SaunierLa GardeSalon-de-ProvenceRognacVitrollesAvignonMarseilleMarignaneSaint-ChamondAlessandriaMâconSaint-ÉtienneFos-sur-MerBesançonArlesBaume-les-DamesChalon-sur-SaôneNîmesGenoaMontceau-les-MinesLunelDijonMontpellierLa SpeziaClermont-FerrandMoulinsBastiaRodezAurillacMontluçonPerpignanBourgesRoveretoTrentoContesMeylanManosqueChambéryGrenobleCrollesAlbertvilleAnnemasse
27 Jan282930311 Feb2
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

CrollesCrolles, 27 January: 28.4 µg/m³Crolles, 28 January: 37.5 µg/m³Crolles, 29 January: 31.0 µg/m³Crolles, 30 January: 31.6 µg/m³, 2.2× its usual 14.4Crolles, 31 January: 27.7 µg/m³Crolles, 1 February: 15.7 µg/m³Crolles, 2 February: no readingMeylanMeylan, 27 January: 28.4 µg/m³Meylan, 28 January: 37.5 µg/m³Meylan, 29 January: 31.0 µg/m³Meylan, 30 January: 31.6 µg/m³, 2.0× its usual 15.8Meylan, 31 January: 27.7 µg/m³Meylan, 1 February: 15.7 µg/m³Meylan, 2 February: 9.8 µg/m³GrenobleGrenoble, 27 January: 20.7 µg/m³Grenoble, 28 January: 23.1 µg/m³Grenoble, 29 January: 30.3 µg/m³Grenoble, 30 January: 31.1 µg/m³, 2.2× its usual 14.3Grenoble, 31 January: 26.2 µg/m³Grenoble, 1 February: 20.6 µg/m³Grenoble, 2 February: 11.6 µg/m³AnnemasseAnnemasse, 27 January: 13.3 µg/m³Annemasse, 28 January: 13.5 µg/m³Annemasse, 29 January: 22.1 µg/m³Annemasse, 30 January: 28.5 µg/m³, 2.3× its usual 12.4Annemasse, 31 January: 25.5 µg/m³Annemasse, 1 February: 12.9 µg/m³Annemasse, 2 February: 12.1 µg/m³ContesContes, 27 January: 18.6 µg/m³Contes, 28 January: 22.0 µg/m³Contes, 29 January: 15.2 µg/m³Contes, 30 January: 27.0 µg/m³, 2.0× its usual 13.4Contes, 31 January: 18.9 µg/m³Contes, 1 February: 13.6 µg/m³Contes, 2 February: no readingChambéryChambéry, 27 January: 19.1 µg/m³Chambéry, 28 January: 23.5 µg/m³Chambéry, 29 January: 24.8 µg/m³Chambéry, 30 January: 26.9 µg/m³, 2.2× its usual 12.1Chambéry, 31 January: 18.8 µg/m³Chambéry, 1 February: 16.5 µg/m³Chambéry, 2 February: 10.5 µg/m³ManosqueManosque, 27 January: 20.2 µg/m³Manosque, 28 January: 18.7 µg/m³Manosque, 29 January: 21.2 µg/m³Manosque, 30 January: 26.6 µg/m³, 2.1× its usual 12.5Manosque, 31 January: 17.8 µg/m³Manosque, 1 February: 11.9 µg/m³Manosque, 2 February: 9.2 µg/m³AlbertvilleAlbertville, 27 January: 19.3 µg/m³Albertville, 28 January: 16.9 µg/m³Albertville, 29 January: 21.1 µg/m³Albertville, 30 January: 25.7 µg/m³, 2.3× its usual 11.1Albertville, 31 January: 22.9 µg/m³Albertville, 1 February: 17.8 µg/m³Albertville, 2 February: 14.1 µg/m³27 Jan282930311 Feb2
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
AnnemasseAuvergne-Rhône-Alpes, France1 28.530 January12.42.3×
AlbertvilleAuvergne-Rhône-Alpes, France1 25.730 January11.12.3×
CrollesAuvergne-Rhône-Alpes, France1 31.630 January14.42.2×
GrenobleAuvergne-Rhône-Alpes, France1 31.130 January14.32.2×
ChambéryAuvergne-Rhône-Alpes, France1 26.930 January12.12.2×
ManosqueProvence-Alpes-Côte d'Azur, France1 26.630 January12.52.1×
MeylanAuvergne-Rhône-Alpes, France1 31.630 January15.82.0×
ContesProvence-Alpes-Côte d'Azur, France1 27.030 January13.42.0×

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 France

Number 26 of 26 episodes in France since our records began, by cities reached.

Bars: cities reached; colour: the level of the episode's highest daily reading. All 26.

Use this page

SmogRank, Auvergne-Rhône-Alpes and Provence-Alpes-Côte d'Azur, France, January 2023: 8 cities with PM2.5 at twice their usual or more, 30 January 2023, smogrank.com/episodes/2023-01-auvergne-rhone-alpes-and-provence-alpes-cote-d-azur-france (accessed 5 October 2026).

Download top 10 (PNG)

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.