SmogRank / Episodes / Mexico

Guanajuato and Querétaro, Mexico, March 2025

For 1 day, on 20 March 2025, 8 cities in Mexico had PM2.5 at least twice their usual for the time of year. The worst reading was Irapuato, Guanajuato, Mexico: 58.9 µg/m³ on 20 March, about 3.2× its usual 18.5.

No cause namedWe have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached8in 1 country
Days120 March 2025
Worst day20 March8 cities counted
Furthest above usual3.2×San Juan del Río

Day by day

20 March 8 cities at twice their usual or more
SalamancaCelayaLeón de los AldamaMoreliaSan Luis PotosíAguascalientesTlaquepaqueZapopanSan Francisco TlalcilalcalpanHacienda Santa FeSanta AnitaTolucaXonacatlánSan Salvador TizatlalliNaucalpan de JuárezEcatepec de MorelosMexico CityPachuca de SotoCiudad NezahualcoyotlLa Providencia Siglo XXICuernavacaZacatepec de HidalgoTlaxcalaAtlixcoApizacoCholulaPueblaTepicTehuacánAbasoloSan Miguel de AllendeMixquiahuala de JuárezGuadalajaraGuanajuatoSan Luis de la PazIrapuatoSan Juan del Río
17 Mar181920212223
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

GuadalajaraGuadalajara, 17 March: 59.9 µg/m³, 2.8× usualGuadalajara, 18 March: 45.3 µg/m³, 2.1× usualGuadalajara, 19 March: 37.0 µg/m³, 1.7× usualGuadalajara, 20 March: 56.3 µg/m³, 2.6× usualGuadalajara, 21 March: 49.5 µg/m³, 2.3× usualGuadalajara, 22 March: 42.7 µg/m³, 2.0× usualGuadalajara, 23 March: 35.9 µg/m³, 1.7× usualIrapuatoIrapuato, 17 March: 27.5 µg/m³, 1.5× usualIrapuato, 18 March: 31.6 µg/m³, 1.7× usualIrapuato, 19 March: 25.1 µg/m³, 1.4× usualIrapuato, 20 March: 58.9 µg/m³, 3.2× usualIrapuato, 21 March: 32.4 µg/m³, 1.8× usualIrapuato, 22 March: 27.6 µg/m³, 1.5× usualIrapuato, 23 March: 25.5 µg/m³, 1.4× usualSan Luis de la PazSan Luis de la Paz, 17 March: 30.1 µg/m³, 1.6× usualSan Luis de la Paz, 18 March: 31.5 µg/m³, 1.6× usualSan Luis de la Paz, 19 March: 33.5 µg/m³, 1.8× usualSan Luis de la Paz, 20 March: 54.6 µg/m³, 2.9× usualSan Luis de la Paz, 21 March: 27.3 µg/m³, 1.4× usualSan Luis de la Paz, 22 March: 28.1 µg/m³, 1.5× usualSan Luis de la Paz, 23 March: 26.7 µg/m³, 1.4× usualSan Juan del RíoSan Juan del Río, 17 March: 18.9 µg/m³, 1.2× usualSan Juan del Río, 18 March: 22.6 µg/m³, 1.4× usualSan Juan del Río, 19 March: 29.3 µg/m³, 1.8× usualSan Juan del Río, 20 March: 50.8 µg/m³, 3.2× usualSan Juan del Río, 21 March: 22.2 µg/m³, 1.4× usualSan Juan del Río, 22 March: 27.4 µg/m³, 1.7× usualSan Juan del Río, 23 March: 22.5 µg/m³, 1.4× usualMixquiahuala de Juá…Mixquiahuala de Juárez, 17 March: 24.6 µg/m³, 1.2× usualMixquiahuala de Juárez, 18 March: 27.8 µg/m³, 1.3× usualMixquiahuala de Juárez, 19 March: 30.7 µg/m³, 1.5× usualMixquiahuala de Juárez, 20 March: 48.6 µg/m³, 2.3× usualMixquiahuala de Juárez, 21 March: 23.6 µg/m³, 1.1× usualMixquiahuala de Juárez, 22 March: 25.1 µg/m³, 1.2× usualMixquiahuala de Juárez, 23 March: 22.2 µg/m³, 1.1× usualGuanajuatoGuanajuato, 17 March: 16.7 µg/m³, 1.2× usualGuanajuato, 18 March: 18.0 µg/m³, 1.3× usualGuanajuato, 19 March: 17.6 µg/m³, 1.2× usualGuanajuato, 20 March: 41.4 µg/m³, 2.9× usualGuanajuato, 21 March: 28.1 µg/m³, 2.0× usualGuanajuato, 22 March: 23.5 µg/m³, 1.7× usualGuanajuato, 23 March: 19.5 µg/m³, 1.4× usualSan Miguel de Allen…San Miguel de Allende, 17 March: 20.9 µg/m³, 1.4× usualSan Miguel de Allende, 18 March: 19.6 µg/m³, 1.4× usualSan Miguel de Allende, 19 March: 16.8 µg/m³, 1.2× usualSan Miguel de Allende, 20 March: 33.9 µg/m³, 2.3× usualSan Miguel de Allende, 21 March: 22.9 µg/m³, 1.6× usualSan Miguel de Allende, 22 March: 21.1 µg/m³, 1.5× usualSan Miguel de Allende, 23 March: 17.5 µg/m³, 1.2× usualAbasoloAbasolo, 17 March: 15.8 µg/m³, 1.1× usualAbasolo, 18 March: 22.1 µg/m³, 1.6× usualAbasolo, 19 March: 14.3 µg/m³, 1.0× usualAbasolo, 20 March: 31.9 µg/m³, 2.3× usualAbasolo, 21 March: 14.5 µg/m³, 1.0× usualAbasolo, 22 March: 16.8 µg/m³, 1.2× usualAbasolo, 23 March: 17.1 µg/m³, 1.2× usual17 Mar181920212223
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
San Juan del RíoQuerétaro, Mexico1 50.820 March15.93.2×
IrapuatoGuanajuato, Mexico1 58.920 March18.53.2×
GuanajuatoGuanajuato, Mexico1 41.420 March14.22.9×
San Luis de la PazGuanajuato, Mexico1 54.620 March19.12.9×
GuadalajaraJalisco, Mexico1 59.917 March21.52.8×
San Miguel de AllendeGuanajuato, Mexico1 33.920 March14.52.3×
Mixquiahuala de JuárezHidalgo, Mexico1 48.620 March20.82.3×
AbasoloGuanajuato, Mexico1 31.920 March13.92.3×

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 Mexico

Number 10 of 12 episodes in Mexico since our records began, by cities reached.

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

Use this page

SmogRank, Guanajuato and Querétaro, Mexico, March 2025: 8 cities with PM2.5 at twice their usual or more, 20 March 2025, smogrank.com/episodes/2025-03-guanajuato-and-queretaro-mexico (accessed 2 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.