SmogRank / Episodes / Spain

Madrid, Castille and León and Castille-La Mancha, Spain, August 2023

For 1 day, on 9 August 2023, 8 cities in Spain had PM2.5 at least twice their usual for the time of year. The worst reading was Algete, Madrid, Spain: 36.2 µg/m³ on 9 August, about 3.7× its usual 9.9. Ended 9 August.

No cause namedWe have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached8in 1 country
Days19 August 2023
Worst day9 August8 cities counted
Furthest above usual3.7×Algete

Day by day

9 August 8 cities at twice their usual or more
Torrejón de ArdozCosladaMadridVilla del PradoBurgosToledoValladolidMedina del CampoCalahorraGasteiz / VitoriaAlfaroLaudio / LlodioCiudad RealDurangoBilbaoBeasainSalamancaAzpeitiaBermeoZarautzDonostia / San SebastiánLeónBuñolAngletVilamarxantRibarroja del TuriaSamaValenciaSaguntoGrao de MurviedroOviedoBurrianaCastelló de la PlanaBenicàssimPauLourdesTarbesVila RealLugoOurenseParedesFreamundeles EscaldesFerrolA CoruñaCuencaValdemoroMóstolesPalenciaVillarejo de SalvanésAlcalá de HenaresCollado-VillalbaAlgete
6 Aug789101112
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

AlgeteAlgete, 6 August: 5.6 µg/m³Algete, 7 August: 6.8 µg/m³Algete, 8 August: 12.1 µg/m³Algete, 9 August: 36.2 µg/m³, 3.7× its usual 9.9Algete, 10 August: 20.0 µg/m³Algete, 11 August: 12.6 µg/m³Algete, 12 August: 10.2 µg/m³Alcalá de HenaresAlcalá de Henares, 6 August: 11.3 µg/m³Alcalá de Henares, 7 August: 12.7 µg/m³Alcalá de Henares, 8 August: 23.7 µg/m³Alcalá de Henares, 9 August: 35.6 µg/m³, 3.1× its usual 11.6Alcalá de Henares, 10 August: 23.6 µg/m³Alcalá de Henares, 11 August: 17.5 µg/m³Alcalá de Henares, 12 August: 14.5 µg/m³MóstolesMóstoles, 6 August: 11.3 µg/m³Móstoles, 7 August: 11.8 µg/m³Móstoles, 8 August: 18.5 µg/m³Móstoles, 9 August: 33.0 µg/m³, 2.6× its usual 12.7Móstoles, 10 August: no readingMóstoles, 11 August: no readingMóstoles, 12 August: 16.5 µg/m³ValdemoroValdemoro, 6 August: 12.5 µg/m³Valdemoro, 7 August: 10.6 µg/m³Valdemoro, 8 August: 14.7 µg/m³Valdemoro, 9 August: 32.6 µg/m³, 2.2× its usual 14.5Valdemoro, 10 August: 18.8 µg/m³Valdemoro, 11 August: 19.7 µg/m³Valdemoro, 12 August: 14.6 µg/m³Collado-VillalbaCollado-Villalba, 6 August: 11.6 µg/m³Collado-Villalba, 7 August: 17.9 µg/m³Collado-Villalba, 8 August: 25.1 µg/m³Collado-Villalba, 9 August: 30.8 µg/m³, 3.5× its usual 8.7Collado-Villalba, 10 August: 16.8 µg/m³Collado-Villalba, 11 August: 15.0 µg/m³Collado-Villalba, 12 August: 15.5 µg/m³Villarejo de Salvan…Villarejo de Salvanés, 6 August: 7.1 µg/m³Villarejo de Salvanés, 7 August: 4.7 µg/m³Villarejo de Salvanés, 8 August: 20.8 µg/m³Villarejo de Salvanés, 9 August: 27.6 µg/m³, 2.8× its usual 9.7Villarejo de Salvanés, 10 August: 12.2 µg/m³Villarejo de Salvanés, 11 August: 9.2 µg/m³Villarejo de Salvanés, 12 August: 9.1 µg/m³CuencaCuenca, 6 August: 12.4 µg/m³Cuenca, 7 August: 10.7 µg/m³Cuenca, 8 August: 15.6 µg/m³Cuenca, 9 August: 27.5 µg/m³, 2.1× its usual 13.0Cuenca, 10 August: 39.2 µg/m³Cuenca, 11 August: 15.8 µg/m³Cuenca, 12 August: 13.7 µg/m³PalenciaPalencia, 6 August: 5.7 µg/m³Palencia, 7 August: 7.4 µg/m³Palencia, 8 August: 11.9 µg/m³Palencia, 9 August: 27.4 µg/m³, 2.7× its usual 10.1Palencia, 10 August: 12.7 µg/m³Palencia, 11 August: 11.5 µg/m³Palencia, 12 August: 11.1 µg/m³6 Aug789101112
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
AlgeteMadrid, Spain1 36.29 August9.93.7×
Collado-VillalbaMadrid, Spain1 30.89 August8.73.5×
Alcalá de HenaresMadrid, Spain1 35.69 August11.63.1×
Villarejo de SalvanésMadrid, Spain1 27.69 August9.72.8×
PalenciaCastille and León, Spain1 27.49 August10.12.7×
MóstolesMadrid, Spain1 33.09 August12.72.6×
ValdemoroMadrid, Spain1 32.69 August14.52.2×
CuencaCastille-La Mancha, Spain1 27.59 August13.02.1×

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 Spain

Number 41 of 41 episodes in Spain since our records began, by cities reached.

Bars: cities reached; colour: the level of the episode's highest daily reading. All 41.

Use this page

SmogRank, Madrid, Castille and León and Castille-La Mancha, Spain, August 2023: 8 cities with PM2.5 at twice their usual or more, 9 August 2023, smogrank.com/episodes/2023-08-madrid-castille-and-leon-and-castille-la-mancha-spain (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.