SmogRank / Episodes / Mexico
Southern Mexico, 5 to 9 January 2026
For 5 days, from 5 to 9 January 2026, 12 cities in Mexico had PM2.5 at least twice their usual for the time of year. The worst reading was Aguascalientes, Aguascalientes, Mexico: 128.4 µg/m³ on 6 January, about 4.5× its usual 28.7.
No cause named We have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached 12 in 1 country
Days 5 5 to 9 January 2026
Worst day 6 January 6 cities counted
Furthest above usual 4.5× Aguascalientes
Day by day
Play 6 January 6 cities at twice their usual or more
Xonacatlán Naucalpan de Juárez Mexico City Celaya Ciudad Nezahualcoyotl San Luis de la Paz Cuernavaca Salamanca Tulancingo Guanajuato Zacatepec de Hidalgo San Martin Texmelucan de Labastida Silao de la Victoria Tlaxcala Apizaco Atlixco Puebla San Luis Potosí Tlaquepaque Guadalajara Hacienda Santa Fe Zapopan Santa Anita Yecapixtla Tula de Allende Tehuacán La Providencia Siglo XXI San Miguel de Allende León de los Aldama Mixquiahuala de Juárez Irapuato San Juan del Río Abasolo Santiago de Querétaro Aguascalientes 2 Jan 3 4 5 6 7 8 9 10 11 12 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
Aguascalientes Aguascalientes, 2 January: 47.9 µg/m³ Aguascalientes, 3 January: 39.7 µg/m³ Aguascalientes, 4 January: 114.9 µg/m³ Aguascalientes, 5 January: 103.5 µg/m³, 3.7× its usual 27.7 Aguascalientes, 6 January: 128.4 µg/m³, 4.5× its usual 28.7 Aguascalientes, 7 January: 57.3 µg/m³ Aguascalientes, 8 January: 41.6 µg/m³ Aguascalientes, 9 January: 36.7 µg/m³ Aguascalientes, 10 January: 43.4 µg/m³ Aguascalientes, 11 January: 23.7 µg/m³ Aguascalientes, 12 January: 29.4 µg/m³ San Juan del Río San Juan del Río, 2 January: 16.3 µg/m³ San Juan del Río, 3 January: 19.8 µg/m³ San Juan del Río, 4 January: 14.7 µg/m³ San Juan del Río, 5 January: 30.7 µg/m³, 2.5× its usual 12.5 San Juan del Río, 6 January: 26.4 µg/m³, 2.1× its usual 12.6 San Juan del Río, 7 January: 25.7 µg/m³, 2.0× its usual 12.7 San Juan del Río, 8 January: 28.2 µg/m³, 2.1× its usual 13.3 San Juan del Río, 9 January: 26.2 µg/m³ San Juan del Río, 10 January: 20.8 µg/m³ San Juan del Río, 11 January: 6.1 µg/m³ San Juan del Río, 12 January: 17.5 µg/m³ Abasolo Abasolo, 2 January: 27.5 µg/m³ Abasolo, 3 January: 25.0 µg/m³ Abasolo, 4 January: 20.1 µg/m³ Abasolo, 5 January: 29.6 µg/m³, 2.1× its usual 13.8 Abasolo, 6 January: 31.5 µg/m³, 2.2× its usual 14.2 Abasolo, 7 January: 39.8 µg/m³, 2.8× its usual 14.4 Abasolo, 8 January: 25.2 µg/m³ Abasolo, 9 January: 24.9 µg/m³ Abasolo, 10 January: 24.7 µg/m³ Abasolo, 11 January: 9.3 µg/m³ Abasolo, 12 January: 10.2 µg/m³ San Miguel de Allen… San Miguel de Allende, 2 January: 21.2 µg/m³ San Miguel de Allende, 3 January: 20.9 µg/m³ San Miguel de Allende, 4 January: 15.6 µg/m³ San Miguel de Allende, 5 January: 25.7 µg/m³, 2.2× its usual 11.8 San Miguel de Allende, 6 January: 27.0 µg/m³, 2.3× its usual 11.9 San Miguel de Allende, 7 January: 26.2 µg/m³, 2.2× its usual 11.9 San Miguel de Allende, 8 January: no reading San Miguel de Allende, 9 January: no reading San Miguel de Allende, 10 January: no reading San Miguel de Allende, 11 January: 7.5 µg/m³ San Miguel de Allende, 12 January: 9.4 µg/m³ Santiago de Queréta… Santiago de Querétaro, 2 January: 22.6 µg/m³ Santiago de Querétaro, 3 January: 26.1 µg/m³ Santiago de Querétaro, 4 January: 14.2 µg/m³ Santiago de Querétaro, 5 January: 28.5 µg/m³ Santiago de Querétaro, 6 January: 42.3 µg/m³, 2.8× its usual 15.0 Santiago de Querétaro, 7 January: 29.8 µg/m³ Santiago de Querétaro, 8 January: 39.5 µg/m³, 2.4× its usual 16.2 Santiago de Querétaro, 9 January: 32.8 µg/m³ Santiago de Querétaro, 10 January: 30.3 µg/m³ Santiago de Querétaro, 11 January: 5.0 µg/m³ Santiago de Querétaro, 12 January: 8.9 µg/m³ Yecapixtla Yecapixtla, 2 January: no reading Yecapixtla, 3 January: no reading Yecapixtla, 4 January: no reading Yecapixtla, 5 January: no reading Yecapixtla, 6 January: 29.3 µg/m³, 2.0× its usual 14.5 Yecapixtla, 7 January: 29.3 µg/m³, 2.1× its usual 14.0 Yecapixtla, 8 January: 22.6 µg/m³ Yecapixtla, 9 January: 33.4 µg/m³ Yecapixtla, 10 January: 19.3 µg/m³ Yecapixtla, 11 January: 12.5 µg/m³ Yecapixtla, 12 January: 6.7 µg/m³ Irapuato Irapuato, 2 January: 35.6 µg/m³ Irapuato, 3 January: 29.7 µg/m³ Irapuato, 4 January: 30.0 µg/m³ Irapuato, 5 January: 36.2 µg/m³ Irapuato, 6 January: 37.6 µg/m³ Irapuato, 7 January: 45.9 µg/m³, 2.4× its usual 19.5 Irapuato, 8 January: no reading Irapuato, 9 January: no reading Irapuato, 10 January: no reading Irapuato, 11 January: 8.7 µg/m³ Irapuato, 12 January: 14.8 µg/m³ León de los Aldama León de los Aldama, 2 January: 28.8 µg/m³ León de los Aldama, 3 January: 29.1 µg/m³ León de los Aldama, 4 January: 22.0 µg/m³ León de los Aldama, 5 January: 29.4 µg/m³ León de los Aldama, 6 January: 32.2 µg/m³ León de los Aldama, 7 January: 38.3 µg/m³, 2.3× its usual 17.0 León de los Aldama, 8 January: no reading León de los Aldama, 9 January: no reading León de los Aldama, 10 January: no reading León de los Aldama, 11 January: 12.7 µg/m³ León de los Aldama, 12 January: 15.4 µg/m³ Mixquiahuala de Juá… Mixquiahuala de Juárez, 2 January: 22.8 µg/m³ Mixquiahuala de Juárez, 3 January: 27.8 µg/m³ Mixquiahuala de Juárez, 4 January: 22.8 µg/m³ Mixquiahuala de Juárez, 5 January: 29.9 µg/m³ Mixquiahuala de Juárez, 6 January: 34.8 µg/m³ Mixquiahuala de Juárez, 7 January: 34.4 µg/m³ Mixquiahuala de Juárez, 8 January: 44.9 µg/m³, 2.4× its usual 18.5 Mixquiahuala de Juárez, 9 January: 44.3 µg/m³, 2.4× its usual 18.2 Mixquiahuala de Juárez, 10 January: 32.4 µg/m³ Mixquiahuala de Juárez, 11 January: 6.5 µg/m³ Mixquiahuala de Juárez, 12 January: 10.9 µg/m³ La Providencia Sigl… La Providencia Siglo XXI, 2 January: 15.3 µg/m³ La Providencia Siglo XXI, 3 January: 19.9 µg/m³ La Providencia Siglo XXI, 4 January: 17.0 µg/m³ La Providencia Siglo XXI, 5 January: 21.8 µg/m³ La Providencia Siglo XXI, 6 January: 23.2 µg/m³ La Providencia Siglo XXI, 7 January: 22.6 µg/m³ La Providencia Siglo XXI, 8 January: 40.9 µg/m³, 2.2× its usual 18.6 La Providencia Siglo XXI, 9 January: 39.6 µg/m³, 2.1× its usual 18.5 La Providencia Siglo XXI, 10 January: 30.9 µg/m³ La Providencia Siglo XXI, 11 January: 5.6 µg/m³ La Providencia Siglo XXI, 12 January: 12.1 µg/m³ Tehuacán Tehuacán, 2 January: 21.0 µg/m³ Tehuacán, 3 January: 21.5 µg/m³ Tehuacán, 4 January: 17.7 µg/m³ Tehuacán, 5 January: 25.3 µg/m³ Tehuacán, 6 January: 27.3 µg/m³ Tehuacán, 7 January: 26.0 µg/m³ Tehuacán, 8 January: 33.4 µg/m³, 2.2× its usual 15.2 Tehuacán, 9 January: 31.9 µg/m³, 2.1× its usual 15.3 Tehuacán, 10 January: 28.3 µg/m³ Tehuacán, 11 January: 13.9 µg/m³ Tehuacán, 12 January: 3.8 µg/m³ Tula de Allende Tula de Allende, 2 January: 18.3 µg/m³ Tula de Allende, 3 January: 20.3 µg/m³ Tula de Allende, 4 January: 18.9 µg/m³ Tula de Allende, 5 January: 24.5 µg/m³ Tula de Allende, 6 January: 26.1 µg/m³ Tula de Allende, 7 January: 25.5 µg/m³ Tula de Allende, 8 January: 31.6 µg/m³, 2.1× its usual 15.3 Tula de Allende, 9 January: 31.9 µg/m³, 2.1× its usual 15.3 Tula de Allende, 10 January: 23.8 µg/m³ Tula de Allende, 11 January: 6.6 µg/m³ Tula de Allende, 12 January: 23.4 µg/m³ 2 Jan 4 6 8 10 12 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. Good 0–50
Moderate 51–100
Sensitive groups 101–150
Unhealthy 151–200
Very unhealthy 201–300
Hazardous 301+
Every city it reached
City Days Highest Usual Above usual
Aguascalientes Aguascalientes, Mexico 2 6 January 28.7 4.5× Santiago de Querétaro Querétaro, Mexico 2 6 January 15.0 2.8× Abasolo Guanajuato, Mexico 3 7 January 14.4 2.8× San Juan del Río Querétaro, Mexico 4 5 January 12.5 2.5× Irapuato Guanajuato, Mexico 1 7 January 19.5 2.4× Mixquiahuala de Juárez Hidalgo, Mexico 2 8 January 18.5 2.4× León de los Aldama Guanajuato, Mexico 1 7 January 17.0 2.3× San Miguel de Allende Guanajuato, Mexico 3 6 January 11.9 2.3× La Providencia Siglo XXI Hidalgo, Mexico 2 8 January 18.6 2.2× Tehuacán Puebla, Mexico 2 8 January 15.2 2.2× Tula de Allende Hidalgo, Mexico 2 9 January 15.3 2.1× Yecapixtla Morelos, Mexico 2 6 January 14.5 2.0×
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 Mexico
Number 5 of 16 episodes in Mexico since our records began, by cities reached.
Southern Mexico, 1 January 2026 20 Southern United States and Mexico, June 2023 17 Southern Mexico, June 2024 16 Southern Mexico, January 2024 14 Southern Mexico, 5 to 9 January 2026 12 Northern Mexico and United States, May 2025 12 Southern Mexico, December 2023 10 Southern Mexico, June 2023 10 Hidalgo, Puebla and Querétaro, Mexico, November 2025 9 Guanajuato, México and Mexico City, Mexico, December 2024 9 Southern United States and Mexico, April 2024 9 Northern Mexico and United States, March and April 2025 8 Bars: cities reached; colour: the level of the episode's highest daily reading. All 16 .
Use this page SmogRank, Southern Mexico, 5 to 9 January 2026: 12 cities with PM2.5 at twice their usual or more, 5 to 9 January 2026, smogrank.com/episodes/2026-01-05-southern-mexico (accessed 4 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.
