SmogRank / Episodes / United States
Southern United States and Mexico, May 2024
For 10 days, from 19 to 28 May 2024, 32 cities in the United States and Mexico had PM2.5 at least twice their usual for the time of year. The worst reading was Saltillo, Coahuila, Mexico: 74.2 µg/m³ on 26 May, about 4.4× its usual 16.7.
No cause named We have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached 32 in 2 countries
Days 10 19 to 28 May 2024
Worst day 27 May 24 cities counted
Furthest above usual 5.1× Live Oak
Day by day
Play 27 May 24 cities at twice their usual or more
Belton Port Arthur Denton Piedras Negras Lafayette Ada Lawton McAlester Moore Oklahoma City Fort Smith Heroica Matamoros Cadereyta Jiménez Monterrey Little Rock Texarkana Shreveport Fort Worth Conroe Ciudad Apodaca Houston Baytown Eagle Pass La Porte San Antonio College Station Laredo Sulphur Saginaw Corsicana Galveston Missouri City Dallas Austin Pasadena Mission Bend Taylor San Marcos Saltillo Edinburg Mission Corpus Christi Live Oak 16 May 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 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
Mission Mission, 16 May: 51.2 µg/m³, 4.1× usual Mission, 17 May: 20.9 µg/m³, 1.7× usual Mission, 18 May: 25.6 µg/m³, 2.0× usual Mission, 19 May: 39.1 µg/m³, 3.1× usual Mission, 20 May: 43.3 µg/m³, 3.5× usual Mission, 21 May: 40.0 µg/m³, 3.2× usual Mission, 22 May: 38.7 µg/m³, 3.1× usual Mission, 23 May: 37.6 µg/m³, 3.0× usual Mission, 24 May: 55.6 µg/m³, 4.4× usual Mission, 25 May: 47.4 µg/m³, 3.8× usual Mission, 26 May: 57.5 µg/m³, 4.6× usual Mission, 27 May: 58.4 µg/m³, 4.7× usual Mission, 28 May: 39.4 µg/m³, 3.2× usual Mission, 29 May: 14.6 µg/m³, 1.2× usual Mission, 30 May: 26.4 µg/m³, 2.1× usual Mission, 31 May: 30.2 µg/m³, 2.4× usual Edinburg Edinburg, 16 May: 46.3 µg/m³, 4.1× usual Edinburg, 17 May: 18.8 µg/m³, 1.7× usual Edinburg, 18 May: 23.7 µg/m³, 2.1× usual Edinburg, 19 May: 30.5 µg/m³, 2.7× usual Edinburg, 20 May: 35.3 µg/m³, 3.1× usual Edinburg, 21 May: 36.2 µg/m³, 3.2× usual Edinburg, 22 May: 31.7 µg/m³, 2.8× usual Edinburg, 23 May: no reading Edinburg, 24 May: 47.0 µg/m³, 4.2× usual Edinburg, 25 May: 38.4 µg/m³, 3.4× usual Edinburg, 26 May: 49.6 µg/m³, 4.4× usual Edinburg, 27 May: 52.4 µg/m³, 4.6× usual Edinburg, 28 May: 30.3 µg/m³, 2.7× usual Edinburg, 29 May: 13.0 µg/m³, 1.2× usual Edinburg, 30 May: 23.4 µg/m³, 2.1× usual Edinburg, 31 May: 26.0 µg/m³, 2.3× usual Corpus Christi Corpus Christi, 16 May: 38.8 µg/m³, 3.5× usual Corpus Christi, 17 May: 10.1 µg/m³, 0.9× usual Corpus Christi, 18 May: 23.0 µg/m³, 2.1× usual Corpus Christi, 19 May: 32.2 µg/m³, 2.9× usual Corpus Christi, 20 May: 29.8 µg/m³, 2.7× usual Corpus Christi, 21 May: 38.2 µg/m³, 3.5× usual Corpus Christi, 22 May: 32.6 µg/m³, 3.0× usual Corpus Christi, 23 May: 34.6 µg/m³, 3.1× usual Corpus Christi, 24 May: 33.9 µg/m³, 3.1× usual Corpus Christi, 25 May: 35.1 µg/m³, 3.2× usual Corpus Christi, 26 May: 41.2 µg/m³, 3.7× usual Corpus Christi, 27 May: 51.9 µg/m³, 4.7× usual Corpus Christi, 28 May: 25.9 µg/m³, 2.4× usual Corpus Christi, 29 May: 15.2 µg/m³, 1.4× usual Corpus Christi, 30 May: 21.8 µg/m³, 2.0× usual Corpus Christi, 31 May: 16.5 µg/m³, 1.5× usual Eagle Pass Eagle Pass, 16 May: 30.5 µg/m³, 2.9× usual Eagle Pass, 17 May: no reading Eagle Pass, 18 May: 7.8 µg/m³, 0.7× usual Eagle Pass, 19 May: no reading Eagle Pass, 20 May: no reading Eagle Pass, 21 May: no reading Eagle Pass, 22 May: no reading Eagle Pass, 23 May: no reading Eagle Pass, 24 May: 28.9 µg/m³, 2.8× usual Eagle Pass, 25 May: 36.0 µg/m³, 3.4× usual Eagle Pass, 26 May: 25.3 µg/m³, 2.4× usual Eagle Pass, 27 May: 30.5 µg/m³, 2.9× usual Eagle Pass, 28 May: 27.2 µg/m³, 2.6× usual Eagle Pass, 29 May: 8.2 µg/m³, 0.8× usual Eagle Pass, 30 May: 22.4 µg/m³, 2.1× usual Eagle Pass, 31 May: 18.4 µg/m³, 1.8× usual Laredo Laredo, 16 May: no reading Laredo, 17 May: 7.1 µg/m³, 0.6× usual Laredo, 18 May: 15.3 µg/m³, 1.3× usual Laredo, 19 May: 31.0 µg/m³, 2.6× usual Laredo, 20 May: 34.3 µg/m³, 2.9× usual Laredo, 21 May: 38.9 µg/m³, 3.2× usual Laredo, 22 May: 42.0 µg/m³, 3.5× usual Laredo, 23 May: no reading Laredo, 24 May: 39.0 µg/m³, 3.3× usual Laredo, 25 May: 42.3 µg/m³, 3.5× usual Laredo, 26 May: 36.9 µg/m³, 3.1× usual Laredo, 27 May: 39.4 µg/m³, 3.3× usual Laredo, 28 May: 29.6 µg/m³, 2.5× usual Laredo, 29 May: 12.7 µg/m³, 1.1× usual Laredo, 30 May: 23.9 µg/m³, 2.0× usual Laredo, 31 May: 22.6 µg/m³, 1.9× usual Live Oak Live Oak, 16 May: 16.9 µg/m³, 1.8× usual Live Oak, 17 May: 9.1 µg/m³, 1.0× usual Live Oak, 18 May: 15.8 µg/m³, 1.7× usual Live Oak, 19 May: 27.2 µg/m³, 2.9× usual Live Oak, 20 May: 23.4 µg/m³, 2.5× usual Live Oak, 21 May: 33.2 µg/m³, 3.5× usual Live Oak, 22 May: 36.8 µg/m³, 3.9× usual Live Oak, 23 May: 38.2 µg/m³, 4.0× usual Live Oak, 24 May: 42.7 µg/m³, 4.5× usual Live Oak, 25 May: 39.3 µg/m³, 4.1× usual Live Oak, 26 May: 40.1 µg/m³, 4.2× usual Live Oak, 27 May: 48.0 µg/m³, 5.1× usual Live Oak, 28 May: 28.4 µg/m³, 3.0× usual Live Oak, 29 May: 9.7 µg/m³, 1.0× usual Live Oak, 30 May: 24.5 µg/m³, 2.6× usual Live Oak, 31 May: 11.2 µg/m³, 1.2× usual Saltillo Saltillo, 16 May: no reading Saltillo, 17 May: no reading Saltillo, 18 May: no reading Saltillo, 19 May: 22.4 µg/m³, 1.3× usual Saltillo, 20 May: no reading Saltillo, 21 May: 69.1 µg/m³, 4.1× usual Saltillo, 22 May: no reading Saltillo, 23 May: no reading Saltillo, 24 May: no reading Saltillo, 25 May: no reading Saltillo, 26 May: 74.2 µg/m³, 4.4× usual Saltillo, 27 May: no reading Saltillo, 28 May: no reading Saltillo, 29 May: no reading Saltillo, 30 May: no reading Saltillo, 31 May: no reading Dallas Dallas, 16 May: 10.1 µg/m³, 1.0× usual Dallas, 17 May: 7.4 µg/m³, 0.7× usual Dallas, 18 May: 10.2 µg/m³, 1.0× usual Dallas, 19 May: 14.5 µg/m³, 1.4× usual Dallas, 20 May: 14.2 µg/m³, 1.4× usual Dallas, 21 May: 31.5 µg/m³, 3.1× usual Dallas, 22 May: 26.2 µg/m³, 2.6× usual Dallas, 23 May: 18.4 µg/m³, 1.8× usual Dallas, 24 May: 27.8 µg/m³, 2.8× usual Dallas, 25 May: 30.8 µg/m³, 3.0× usual Dallas, 26 May: 24.4 µg/m³, 2.4× usual Dallas, 27 May: 39.3 µg/m³, 3.9× usual Dallas, 28 May: 11.9 µg/m³, 1.2× usual Dallas, 29 May: 10.0 µg/m³, 1.0× usual Dallas, 30 May: 9.5 µg/m³, 0.9× usual Dallas, 31 May: 4.1 µg/m³, 0.4× usual Austin Austin, 16 May: 13.0 µg/m³, 1.2× usual Austin, 17 May: 7.8 µg/m³, 0.7× usual Austin, 18 May: 14.5 µg/m³, 1.4× usual Austin, 19 May: 21.8 µg/m³, 2.1× usual Austin, 20 May: 18.6 µg/m³, 1.8× usual Austin, 21 May: 30.5 µg/m³, 2.9× usual Austin, 22 May: 29.6 µg/m³, 2.8× usual Austin, 23 May: 25.7 µg/m³, 2.4× usual Austin, 24 May: 33.9 µg/m³, 3.2× usual Austin, 25 May: 32.9 µg/m³, 3.1× usual Austin, 26 May: 33.7 µg/m³, 3.2× usual Austin, 27 May: 40.6 µg/m³, 3.9× usual Austin, 28 May: 23.3 µg/m³, 2.2× usual Austin, 29 May: 9.9 µg/m³, 0.9× usual Austin, 30 May: 15.3 µg/m³, 1.5× usual Austin, 31 May: 8.5 µg/m³, 0.8× usual Saginaw Saginaw, 16 May: 14.6 µg/m³, 1.6× usual Saginaw, 17 May: 9.8 µg/m³, 1.1× usual Saginaw, 18 May: 12.5 µg/m³, 1.4× usual Saginaw, 19 May: 16.7 µg/m³, 1.9× usual Saginaw, 20 May: 15.8 µg/m³, 1.8× usual Saginaw, 21 May: 30.3 µg/m³, 3.4× usual Saginaw, 22 May: 32.7 µg/m³, 3.6× usual Saginaw, 23 May: no reading Saginaw, 24 May: 29.4 µg/m³, 3.3× usual Saginaw, 25 May: 31.1 µg/m³, 3.5× usual Saginaw, 26 May: 18.3 µg/m³, 2.0× usual Saginaw, 27 May: 24.7 µg/m³, 2.7× usual Saginaw, 28 May: 16.4 µg/m³, 1.8× usual Saginaw, 29 May: 12.3 µg/m³, 1.4× usual Saginaw, 30 May: 13.6 µg/m³, 1.5× usual Saginaw, 31 May: 6.9 µg/m³, 0.8× usual College Station College Station, 16 May: 9.8 µg/m³, 1.2× usual College Station, 17 May: 7.5 µg/m³, 0.9× usual College Station, 18 May: 12.9 µg/m³, 1.5× usual College Station, 19 May: 14.8 µg/m³, 1.8× usual College Station, 20 May: 15.1 µg/m³, 1.8× usual College Station, 21 May: 27.7 µg/m³, 3.3× usual College Station, 22 May: 21.2 µg/m³, 2.5× usual College Station, 23 May: no reading College Station, 24 May: 25.6 µg/m³, 3.0× usual College Station, 25 May: 26.0 µg/m³, 3.1× usual College Station, 26 May: 29.3 µg/m³, 3.5× usual College Station, 27 May: 24.9 µg/m³, 3.0× usual College Station, 28 May: 20.7 µg/m³, 2.5× usual College Station, 29 May: 9.1 µg/m³, 1.1× usual College Station, 30 May: 11.2 µg/m³, 1.3× usual College Station, 31 May: 3.8 µg/m³, 0.5× usual Corsicana Corsicana, 16 May: 11.6 µg/m³, 1.2× usual Corsicana, 17 May: 6.4 µg/m³, 0.7× usual Corsicana, 18 May: 9.4 µg/m³, 1.0× usual Corsicana, 19 May: 16.1 µg/m³, 1.7× usual Corsicana, 20 May: 12.2 µg/m³, 1.3× usual Corsicana, 21 May: 27.1 µg/m³, 2.9× usual Corsicana, 22 May: 26.1 µg/m³, 2.8× usual Corsicana, 23 May: no reading Corsicana, 24 May: 24.9 µg/m³, 2.6× usual Corsicana, 25 May: 29.1 µg/m³, 3.1× usual Corsicana, 26 May: 29.4 µg/m³, 3.1× usual Corsicana, 27 May: 33.8 µg/m³, 3.6× usual Corsicana, 28 May: 14.0 µg/m³, 1.5× usual Corsicana, 29 May: 10.2 µg/m³, 1.1× usual Corsicana, 30 May: 10.7 µg/m³, 1.1× usual Corsicana, 31 May: 3.7 µg/m³, 0.4× usual Mission Bend Mission Bend, 16 May: 15.2 µg/m³, 1.4× usual Mission Bend, 17 May: 13.6 µg/m³, 1.3× usual Mission Bend, 18 May: 19.0 µg/m³, 1.8× usual Mission Bend, 19 May: 11.3 µg/m³, 1.1× usual Mission Bend, 20 May: 16.2 µg/m³, 1.5× usual Mission Bend, 21 May: 26.9 µg/m³, 2.5× usual Mission Bend, 22 May: 19.8 µg/m³, 1.9× usual Mission Bend, 23 May: no reading Mission Bend, 24 May: 19.9 µg/m³, 1.9× usual Mission Bend, 25 May: 24.7 µg/m³, 2.3× usual Mission Bend, 26 May: 29.9 µg/m³, 2.8× usual Mission Bend, 27 May: 43.1 µg/m³, 4.1× usual Mission Bend, 28 May: no reading Mission Bend, 29 May: no reading Mission Bend, 30 May: 8.2 µg/m³, 0.8× usual Mission Bend, 31 May: 5.9 µg/m³, 0.6× usual Conroe Conroe, 16 May: 14.7 µg/m³, 1.4× usual Conroe, 17 May: 11.0 µg/m³, 1.0× usual Conroe, 18 May: 17.1 µg/m³, 1.6× usual Conroe, 19 May: 21.3 µg/m³, 2.0× usual Conroe, 20 May: 18.3 µg/m³, 1.7× usual Conroe, 21 May: 26.6 µg/m³, 2.5× usual Conroe, 22 May: 21.2 µg/m³, 2.0× usual Conroe, 23 May: no reading Conroe, 24 May: 23.1 µg/m³, 2.2× usual Conroe, 25 May: 26.4 µg/m³, 2.5× usual Conroe, 26 May: 32.8 µg/m³, 3.1× usual Conroe, 27 May: 29.3 µg/m³, 2.8× usual Conroe, 28 May: 25.0 µg/m³, 2.4× usual Conroe, 29 May: 11.8 µg/m³, 1.1× usual Conroe, 30 May: 8.7 µg/m³, 0.8× usual Conroe, 31 May: 6.4 µg/m³, 0.6× usual Houston Houston, 16 May: 15.0 µg/m³, 1.2× usual Houston, 17 May: no reading Houston, 18 May: 21.8 µg/m³, 1.8× usual Houston, 19 May: 12.6 µg/m³, 1.0× usual Houston, 20 May: 13.8 µg/m³, 1.1× usual Houston, 21 May: 26.0 µg/m³, 2.1× usual Houston, 22 May: 21.1 µg/m³, 1.7× usual Houston, 23 May: 20.4 µg/m³, 1.7× usual Houston, 24 May: 20.1 µg/m³, 1.7× usual Houston, 25 May: 25.2 µg/m³, 2.1× usual Houston, 26 May: 28.3 µg/m³, 2.3× usual Houston, 27 May: 40.5 µg/m³, 3.3× usual Houston, 28 May: 18.8 µg/m³, 1.6× usual Houston, 29 May: 15.6 µg/m³, 1.3× usual Houston, 30 May: 10.9 µg/m³, 0.9× usual Houston, 31 May: 7.5 µg/m³, 0.6× usual Fort Worth Fort Worth, 16 May: 9.5 µg/m³, 1.1× usual Fort Worth, 17 May: 6.1 µg/m³, 0.7× usual Fort Worth, 18 May: 10.3 µg/m³, 1.2× usual Fort Worth, 19 May: 14.9 µg/m³, 1.7× usual Fort Worth, 20 May: 13.9 µg/m³, 1.6× usual Fort Worth, 21 May: 25.9 µg/m³, 2.9× usual Fort Worth, 22 May: 23.7 µg/m³, 2.7× usual Fort Worth, 23 May: no reading Fort Worth, 24 May: 25.0 µg/m³, 2.8× usual Fort Worth, 25 May: 27.2 µg/m³, 3.1× usual Fort Worth, 26 May: 21.5 µg/m³, 2.4× usual Fort Worth, 27 May: 27.5 µg/m³, 3.1× usual Fort Worth, 28 May: 11.9 µg/m³, 1.4× usual Fort Worth, 29 May: 9.3 µg/m³, 1.1× usual Fort Worth, 30 May: 10.1 µg/m³, 1.1× usual Fort Worth, 31 May: 4.9 µg/m³, 0.6× usual Missouri City Missouri City, 16 May: 15.0 µg/m³, 1.4× usual Missouri City, 17 May: 15.0 µg/m³, 1.4× usual Missouri City, 18 May: 18.1 µg/m³, 1.7× usual Missouri City, 19 May: 12.5 µg/m³, 1.2× usual Missouri City, 20 May: 15.8 µg/m³, 1.5× usual Missouri City, 21 May: 25.7 µg/m³, 2.4× usual Missouri City, 22 May: 20.2 µg/m³, 1.9× usual Missouri City, 23 May: no reading Missouri City, 24 May: 19.8 µg/m³, 1.9× usual Missouri City, 25 May: 24.1 µg/m³, 2.3× usual Missouri City, 26 May: 28.1 µg/m³, 2.7× usual Missouri City, 27 May: 40.4 µg/m³, 3.8× usual Missouri City, 28 May: 19.2 µg/m³, 1.8× usual Missouri City, 29 May: 15.4 µg/m³, 1.5× usual Missouri City, 30 May: 9.4 µg/m³, 0.9× usual Missouri City, 31 May: 7.4 µg/m³, 0.7× usual Taylor Taylor, 16 May: 9.0 µg/m³, 1.3× usual Taylor, 17 May: 6.7 µg/m³, 1.0× usual Taylor, 18 May: 11.4 µg/m³, 1.7× usual Taylor, 19 May: 15.0 µg/m³, 2.2× usual Taylor, 20 May: 15.3 µg/m³, 2.2× usual Taylor, 21 May: 25.1 µg/m³, 3.6× usual Taylor, 22 May: 22.1 µg/m³, 3.2× usual Taylor, 23 May: 17.0 µg/m³, 2.5× usual Taylor, 24 May: 25.4 µg/m³, 3.7× usual Taylor, 25 May: 25.0 µg/m³, 3.6× usual Taylor, 26 May: 28.3 µg/m³, 4.1× usual Taylor, 27 May: 29.9 µg/m³, 4.3× usual Taylor, 28 May: 19.6 µg/m³, 2.8× usual Taylor, 29 May: 6.6 µg/m³, 1.0× usual Taylor, 30 May: no reading Taylor, 31 May: no reading Monterrey Monterrey, 16 May: no reading Monterrey, 17 May: no reading Monterrey, 18 May: no reading Monterrey, 19 May: no reading Monterrey, 20 May: no reading Monterrey, 21 May: no reading Monterrey, 22 May: 45.3 µg/m³, 2.6× usual Monterrey, 23 May: 45.9 µg/m³, 2.6× usual Monterrey, 24 May: 34.9 µg/m³, 2.0× usual Monterrey, 25 May: 38.0 µg/m³, 2.1× usual Monterrey, 26 May: no reading Monterrey, 27 May: no reading Monterrey, 28 May: no reading Monterrey, 29 May: no reading Monterrey, 30 May: no reading Monterrey, 31 May: no reading San Marcos San Marcos, 16 May: 13.0 µg/m³, 1.6× usual San Marcos, 17 May: 6.7 µg/m³, 0.8× usual San Marcos, 18 May: 11.5 µg/m³, 1.4× usual San Marcos, 19 May: 19.9 µg/m³, 2.4× usual San Marcos, 20 May: 15.8 µg/m³, 1.9× usual San Marcos, 21 May: 24.0 µg/m³, 2.9× usual San Marcos, 22 May: 28.5 µg/m³, 3.4× usual San Marcos, 23 May: 21.9 µg/m³, 2.6× usual San Marcos, 24 May: 27.6 µg/m³, 3.3× usual San Marcos, 25 May: 27.7 µg/m³, 3.3× usual San Marcos, 26 May: 30.6 µg/m³, 3.7× usual San Marcos, 27 May: 36.3 µg/m³, 4.4× usual San Marcos, 28 May: 18.6 µg/m³, 2.2× usual San Marcos, 29 May: 10.7 µg/m³, 1.3× usual San Marcos, 30 May: no reading San Marcos, 31 May: no reading San Antonio San Antonio, 16 May: 13.8 µg/m³, 1.4× usual San Antonio, 17 May: 8.5 µg/m³, 0.9× usual San Antonio, 18 May: 13.1 µg/m³, 1.4× usual San Antonio, 19 May: 21.1 µg/m³, 2.2× usual San Antonio, 20 May: 18.5 µg/m³, 1.9× usual San Antonio, 21 May: 24.6 µg/m³, 2.6× usual San Antonio, 22 May: 26.6 µg/m³, 2.8× usual San Antonio, 23 May: 23.5 µg/m³, 2.4× usual San Antonio, 24 May: 31.6 µg/m³, 3.3× usual San Antonio, 25 May: 27.9 µg/m³, 2.9× usual San Antonio, 26 May: 30.9 µg/m³, 3.2× usual San Antonio, 27 May: 33.2 µg/m³, 3.5× usual San Antonio, 28 May: 20.3 µg/m³, 2.1× usual San Antonio, 29 May: 7.2 µg/m³, 0.8× usual San Antonio, 30 May: 18.4 µg/m³, 1.9× usual San Antonio, 31 May: 9.2 µg/m³, 1.0× usual Cadereyta Jiménez Cadereyta Jiménez, 16 May: no reading Cadereyta Jiménez, 17 May: no reading Cadereyta Jiménez, 18 May: no reading Cadereyta Jiménez, 19 May: no reading Cadereyta Jiménez, 20 May: no reading Cadereyta Jiménez, 21 May: no reading Cadereyta Jiménez, 22 May: no reading Cadereyta Jiménez, 23 May: no reading Cadereyta Jiménez, 24 May: 31.5 µg/m³, 2.6× usual Cadereyta Jiménez, 25 May: no reading Cadereyta Jiménez, 26 May: no reading Cadereyta Jiménez, 27 May: no reading Cadereyta Jiménez, 28 May: no reading Cadereyta Jiménez, 29 May: no reading Cadereyta Jiménez, 30 May: no reading Cadereyta Jiménez, 31 May: no reading Shreveport Shreveport, 16 May: 20.0 µg/m³, 2.1× usual Shreveport, 17 May: 11.2 µg/m³, 1.2× usual Shreveport, 18 May: 12.1 µg/m³, 1.3× usual Shreveport, 19 May: 13.0 µg/m³, 1.4× usual Shreveport, 20 May: 14.6 µg/m³, 1.5× usual Shreveport, 21 May: no reading Shreveport, 22 May: no reading Shreveport, 23 May: no reading Shreveport, 24 May: no reading Shreveport, 25 May: 28.8 µg/m³, 3.0× usual Shreveport, 26 May: 28.4 µg/m³, 3.0× usual Shreveport, 27 May: 21.8 µg/m³, 2.3× usual Shreveport, 28 May: 11.0 µg/m³, 1.2× usual Shreveport, 29 May: 11.3 µg/m³, 1.2× usual Shreveport, 30 May: 9.9 µg/m³, 1.0× usual Shreveport, 31 May: 6.0 µg/m³, 0.6× usual Texarkana Texarkana, 16 May: 20.9 µg/m³, 2.1× usual Texarkana, 17 May: 11.1 µg/m³, 1.1× usual Texarkana, 18 May: 12.7 µg/m³, 1.3× usual Texarkana, 19 May: 13.9 µg/m³, 1.4× usual Texarkana, 20 May: 12.9 µg/m³, 1.3× usual Texarkana, 21 May: 21.7 µg/m³, 2.1× usual Texarkana, 22 May: 18.6 µg/m³, 1.8× usual Texarkana, 23 May: no reading Texarkana, 24 May: 18.7 µg/m³, 1.9× usual Texarkana, 25 May: 23.3 µg/m³, 2.3× usual Texarkana, 26 May: 30.8 µg/m³, 3.0× usual Texarkana, 27 May: 13.4 µg/m³, 1.3× usual Texarkana, 28 May: 8.4 µg/m³, 0.8× usual Texarkana, 29 May: 11.5 µg/m³, 1.1× usual Texarkana, 30 May: 9.7 µg/m³, 1.0× usual Texarkana, 31 May: 6.4 µg/m³, 0.6× usual Little Rock Little Rock, 16 May: 15.1 µg/m³, 1.5× usual Little Rock, 17 May: 10.3 µg/m³, 1.0× usual Little Rock, 18 May: 8.2 µg/m³, 0.8× usual Little Rock, 19 May: 10.3 µg/m³, 1.0× usual Little Rock, 20 May: 10.2 µg/m³, 1.0× usual Little Rock, 21 May: 16.6 µg/m³, 1.7× usual Little Rock, 22 May: 16.6 µg/m³, 1.7× usual Little Rock, 23 May: 10.2 µg/m³, 1.0× usual Little Rock, 24 May: 12.4 µg/m³, 1.2× usual Little Rock, 25 May: 15.7 µg/m³, 1.6× usual Little Rock, 26 May: 27.1 µg/m³, 2.7× usual Little Rock, 27 May: 14.8 µg/m³, 1.5× usual Little Rock, 28 May: 8.2 µg/m³, 0.8× usual Little Rock, 29 May: 8.9 µg/m³, 0.9× usual Little Rock, 30 May: 7.5 µg/m³, 0.8× usual Little Rock, 31 May: 8.2 µg/m³, 0.8× usual Pasadena Pasadena, 16 May: no reading Pasadena, 17 May: no reading Pasadena, 18 May: no reading Pasadena, 19 May: no reading Pasadena, 20 May: 14.2 µg/m³, 1.3× usual Pasadena, 21 May: 22.4 µg/m³, 2.1× usual Pasadena, 22 May: 18.0 µg/m³, 1.7× usual Pasadena, 23 May: no reading Pasadena, 24 May: 18.5 µg/m³, 1.7× usual Pasadena, 25 May: 23.5 µg/m³, 2.2× usual Pasadena, 26 May: 27.0 µg/m³, 2.5× usual Pasadena, 27 May: 43.1 µg/m³, 4.0× usual Pasadena, 28 May: 18.6 µg/m³, 1.7× usual Pasadena, 29 May: 13.5 µg/m³, 1.2× usual Pasadena, 30 May: 8.4 µg/m³, 0.8× usual Pasadena, 31 May: 6.8 µg/m³, 0.6× usual Heroica Matamoros Heroica Matamoros, 16 May: 41.7 µg/m³, 1.8× usual Heroica Matamoros, 17 May: 33.8 µg/m³, 1.4× usual Heroica Matamoros, 18 May: 27.6 µg/m³, 1.2× usual Heroica Matamoros, 19 May: 36.8 µg/m³, 1.6× usual Heroica Matamoros, 20 May: 34.4 µg/m³, 1.5× usual Heroica Matamoros, 21 May: 34.7 µg/m³, 1.5× usual Heroica Matamoros, 22 May: 25.3 µg/m³, 1.1× usual Heroica Matamoros, 23 May: no reading Heroica Matamoros, 24 May: 30.5 µg/m³, 1.3× usual Heroica Matamoros, 25 May: 29.4 µg/m³, 1.3× usual Heroica Matamoros, 26 May: 43.3 µg/m³, 1.9× usual Heroica Matamoros, 27 May: 50.5 µg/m³, 2.2× usual Heroica Matamoros, 28 May: 28.8 µg/m³, 1.2× usual Heroica Matamoros, 29 May: 18.1 µg/m³, 0.8× usual Heroica Matamoros, 30 May: 19.4 µg/m³, 0.8× usual Heroica Matamoros, 31 May: 21.5 µg/m³, 0.9× usual Ciudad Apodaca Ciudad Apodaca, 16 May: no reading Ciudad Apodaca, 17 May: no reading Ciudad Apodaca, 18 May: no reading Ciudad Apodaca, 19 May: no reading Ciudad Apodaca, 20 May: no reading Ciudad Apodaca, 21 May: no reading Ciudad Apodaca, 22 May: no reading Ciudad Apodaca, 23 May: no reading Ciudad Apodaca, 24 May: no reading Ciudad Apodaca, 25 May: no reading Ciudad Apodaca, 26 May: no reading Ciudad Apodaca, 27 May: 39.7 µg/m³, 3.3× usual Ciudad Apodaca, 28 May: no reading Ciudad Apodaca, 29 May: no reading Ciudad Apodaca, 30 May: no reading Ciudad Apodaca, 31 May: no reading Baytown Baytown, 16 May: 13.1 µg/m³, 1.1× usual Baytown, 17 May: no reading Baytown, 18 May: 14.6 µg/m³, 1.3× usual Baytown, 19 May: 10.8 µg/m³, 0.9× usual Baytown, 20 May: 14.0 µg/m³, 1.2× usual Baytown, 21 May: 18.0 µg/m³, 1.6× usual Baytown, 22 May: 17.2 µg/m³, 1.5× usual Baytown, 23 May: no reading Baytown, 24 May: 17.9 µg/m³, 1.6× usual Baytown, 25 May: 23.8 µg/m³, 2.1× usual Baytown, 26 May: 24.8 µg/m³, 2.2× usual Baytown, 27 May: 39.3 µg/m³, 3.4× usual Baytown, 28 May: no reading Baytown, 29 May: 11.5 µg/m³, 1.0× usual Baytown, 30 May: no reading Baytown, 31 May: 5.7 µg/m³, 0.5× usual La Porte La Porte, 16 May: 10.7 µg/m³, 1.1× usual La Porte, 17 May: 9.4 µg/m³, 1.0× usual La Porte, 18 May: 12.6 µg/m³, 1.3× usual La Porte, 19 May: 9.4 µg/m³, 1.0× usual La Porte, 20 May: 11.3 µg/m³, 1.2× usual La Porte, 21 May: 15.1 µg/m³, 1.6× usual La Porte, 22 May: 13.9 µg/m³, 1.4× usual La Porte, 23 May: no reading La Porte, 24 May: 14.7 µg/m³, 1.5× usual La Porte, 25 May: 18.9 µg/m³, 2.0× usual La Porte, 26 May: 22.2 µg/m³, 2.3× usual La Porte, 27 May: 33.5 µg/m³, 3.5× usual La Porte, 28 May: 14.2 µg/m³, 1.5× usual La Porte, 29 May: 10.6 µg/m³, 1.1× usual La Porte, 30 May: 7.6 µg/m³, 0.8× usual La Porte, 31 May: 5.6 µg/m³, 0.6× usual Galveston Galveston, 16 May: 10.6 µg/m³, 1.2× usual Galveston, 17 May: 6.9 µg/m³, 0.8× usual Galveston, 18 May: 9.1 µg/m³, 1.0× usual Galveston, 19 May: 8.7 µg/m³, 1.0× usual Galveston, 20 May: 9.7 µg/m³, 1.1× usual Galveston, 21 May: 10.5 µg/m³, 1.2× usual Galveston, 22 May: 11.2 µg/m³, 1.2× usual Galveston, 23 May: no reading Galveston, 24 May: 14.8 µg/m³, 1.6× usual Galveston, 25 May: 17.0 µg/m³, 1.9× usual Galveston, 26 May: 18.6 µg/m³, 2.0× usual Galveston, 27 May: 33.3 µg/m³, 3.7× usual Galveston, 28 May: 14.2 µg/m³, 1.6× usual Galveston, 29 May: 9.2 µg/m³, 1.0× usual Galveston, 30 May: 5.5 µg/m³, 0.6× usual Galveston, 31 May: 5.6 µg/m³, 0.6× usual Sulphur Sulphur, 16 May: 10.4 µg/m³, 1.2× usual Sulphur, 17 May: 9.8 µg/m³, 1.1× usual Sulphur, 18 May: 9.6 µg/m³, 1.1× usual Sulphur, 19 May: 10.1 µg/m³, 1.2× usual Sulphur, 20 May: 9.1 µg/m³, 1.0× usual Sulphur, 21 May: 10.6 µg/m³, 1.2× usual Sulphur, 22 May: 11.0 µg/m³, 1.3× usual Sulphur, 23 May: 10.9 µg/m³, 1.3× usual Sulphur, 24 May: 13.5 µg/m³, 1.6× usual Sulphur, 25 May: 15.1 µg/m³, 1.7× usual Sulphur, 26 May: 14.2 µg/m³, 1.6× usual Sulphur, 27 May: 31.1 µg/m³, 3.6× usual Sulphur, 28 May: 14.9 µg/m³, 1.7× usual Sulphur, 29 May: 9.5 µg/m³, 1.1× usual Sulphur, 30 May: 9.4 µg/m³, 1.1× usual Sulphur, 31 May: 3.4 µg/m³, 0.4× usual 16 May 18 20 22 24 26 28 30 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
Live Oak Texas, United States 9 27 May 9.5 5.1× Corpus Christi Texas, United States 10 27 May 11.0 4.7× Mission Texas, United States 10 27 May 12.5 4.7× Edinburg Texas, United States 9 27 May 11.3 4.6× Saltillo Coahuila, Mexico 2 26 May 16.7 4.4× San Marcos Texas, United States 5 27 May 8.3 4.4× Taylor Texas, United States 5 27 May 6.9 4.3× Mission Bend Texas, United States 3 27 May 10.6 4.1× Pasadena Texas, United States 2 27 May 10.9 4.0× Dallas Texas, United States 5 27 May 10.1 3.9× Austin Texas, United States 7 27 May 10.5 3.9× Missouri City Texas, United States 3 27 May 10.5 3.8× Galveston Texas, United States 1 27 May 9.1 3.7× Saginaw Texas, United States 4 22 May 9.0 3.6× Corsicana Texas, United States 5 27 May 9.4 3.6× Sulphur Louisiana, United States 1 27 May 8.7 3.6× Laredo Texas, United States 9 25 May 12.0 3.5× La Porte Texas, United States 1 27 May 9.6 3.5× College Station Texas, United States 4 26 May 8.4 3.5× San Antonio Texas, United States 5 27 May 9.6 3.5× Eagle Pass Texas, United States 5 25 May 10.5 3.4× Baytown Texas, United States 1 27 May 11.5 3.4× Houston Texas, United States 4 27 May 12.1 3.3× Ciudad Apodaca Nuevo León, Mexico 1 27 May 12.0 3.3× Fort Worth Texas, United States 4 27 May 8.8 3.1× Conroe Texas, United States 5 26 May 10.5 3.1× Texarkana Texas, United States 1 26 May 10.1 3.0× Shreveport Louisiana, United States 2 25 May 9.5 3.0× Little Rock Arkansas, United States 1 26 May 10.0 2.7× Cadereyta Jiménez Nuevo León, Mexico 1 24 May 12.1 2.6× Monterrey Nuevo León, Mexico 4 23 May 17.7 2.6× Heroica Matamoros Tamaulipas, Mexico 1 27 May 23.4 2.2×
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 the United States and Mexico
Number 28 of 142 episodes in the United States and Mexico since our records began, by cities reached.
North-eastern United States and Canada, June and July 2023 280 North-eastern United States and Canada, July 2026 264 North-eastern United States and Canada, May and June 2023 261 North-eastern United States and Canada, July and August 2025 241 North-eastern United States and Canada, July 2023 240 North-eastern United States and Canada, June 2025 196 North-eastern United States and Canada, June 2023 161 North-eastern United States and Canada, July 2025 119 North-western United States and Canada, August 2023 110 North-eastern United States, June 2025 104 North-western United States and Canada, August 2026 99 North-eastern United States and Canada, February 2026 96 Southern United States and Mexico, May 2024 32 Bars: cities reached; colour: the level of the episode's highest daily reading. All 142 .
Use this page SmogRank, Southern United States and Mexico, May 2024: 32 cities with PM2.5 at twice their usual or more, 19 to 28 May 2024, smogrank.com/episodes/2024-05-southern-united-states-and-mexico-2 (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.
