SmogRank / Episodes / United States

Texas and Louisiana, United States, December 2025 to January 2026

For 2 days, from 31 December 2025 to 1 January 2026, 8 cities in the United States had PM2.5 at least twice their usual for the time of year. The worst reading was San Antonio, Texas, United States: 71.0 µg/m³ on 1 January, about 9.3× its usual 7.6.

Likely New Year fireworksIt came on the night of 31 December, when smoke from fireworks often fills the air over many cities at once.
Cities reached8in 1 country
Days231 December 2025 to 1 January 2026
Worst day1 January6 cities counted
Furthest above usual9.3×San Antonio

Day by day

1 January 6 cities at twice their usual or more
BaytownLa PorteGalvestonConroeCollege StationLafayetteCorsicanaTaylorBaton RougePflugervilleBeltonAustinCedar ParkSan MarcosCorpus ChristiNew OrleansChalmetteKennerSulphurHoustonLive OakPasadenaMission BendMissouri CitySan Antonio
28 Dec2930311 Jan234
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

HoustonHouston, 28 December: 7.9 µg/m³Houston, 29 December: 3.4 µg/m³Houston, 30 December: 10.7 µg/m³Houston, 31 December: 30.9 µg/m³, 2.8× its usual 10.9Houston, 1 January: 45.3 µg/m³, 4.2× its usual 10.9Houston, 2 January: 5.9 µg/m³Houston, 3 January: 11.6 µg/m³Houston, 4 January: 9.6 µg/m³San AntonioSan Antonio, 28 December: 6.9 µg/m³San Antonio, 29 December: 2.3 µg/m³San Antonio, 30 December: 8.7 µg/m³San Antonio, 31 December: 29.3 µg/m³, 4.0× its usual 7.4San Antonio, 1 January: 71.0 µg/m³, 9.3× its usual 7.6San Antonio, 2 January: 9.2 µg/m³San Antonio, 3 January: 7.1 µg/m³San Antonio, 4 January: 11.8 µg/m³SulphurSulphur, 28 December: 6.2 µg/m³Sulphur, 29 December: 5.0 µg/m³Sulphur, 30 December: 21.9 µg/m³Sulphur, 31 December: 27.4 µg/m³, 3.9× its usual 7.1Sulphur, 1 January: 16.7 µg/m³Sulphur, 2 January: 8.3 µg/m³Sulphur, 3 January: 10.6 µg/m³Sulphur, 4 January: 8.2 µg/m³KennerKenner, 28 December: 4.8 µg/m³Kenner, 29 December: 3.5 µg/m³Kenner, 30 December: 3.1 µg/m³Kenner, 31 December: 25.4 µg/m³, 3.8× its usual 6.6Kenner, 1 January: 17.2 µg/m³Kenner, 2 January: 5.1 µg/m³Kenner, 3 January: 15.6 µg/m³Kenner, 4 January: 9.7 µg/m³Missouri CityMissouri City, 28 December: 6.8 µg/m³Missouri City, 29 December: 2.7 µg/m³Missouri City, 30 December: 4.9 µg/m³Missouri City, 31 December: 13.8 µg/m³Missouri City, 1 January: 64.5 µg/m³, 7.5× its usual 8.6Missouri City, 2 January: 4.7 µg/m³Missouri City, 3 January: 11.2 µg/m³Missouri City, 4 January: 8.3 µg/m³Mission BendMission Bend, 28 December: 8.1 µg/m³Mission Bend, 29 December: 2.7 µg/m³Mission Bend, 30 December: 4.8 µg/m³Mission Bend, 31 December: 12.5 µg/m³Mission Bend, 1 January: 48.5 µg/m³, 6.6× its usual 7.4Mission Bend, 2 January: 6.9 µg/m³Mission Bend, 3 January: 9.2 µg/m³Mission Bend, 4 January: 5.8 µg/m³PasadenaPasadena, 28 December: 6.4 µg/m³Pasadena, 29 December: 2.2 µg/m³Pasadena, 30 December: 9.3 µg/m³Pasadena, 31 December: 22.1 µg/m³Pasadena, 1 January: 39.2 µg/m³, 4.3× its usual 9.2Pasadena, 2 January: 4.9 µg/m³Pasadena, 3 January: 10.8 µg/m³Pasadena, 4 January: 7.8 µg/m³Live OakLive Oak, 28 December: 7.8 µg/m³Live Oak, 29 December: 3.4 µg/m³Live Oak, 30 December: 4.5 µg/m³Live Oak, 31 December: 13.2 µg/m³Live Oak, 1 January: 28.1 µg/m³, 4.3× its usual 6.6Live Oak, 2 January: 7.9 µg/m³Live Oak, 3 January: 5.9 µg/m³Live Oak, 4 January: 9.8 µg/m³28 Dec2930311 Jan234
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 AntonioTexas, United States2 71.01 January7.69.3×
Missouri CityTexas, United States1 64.51 January8.67.5×
Mission BendTexas, United States1 48.51 January7.46.6×
PasadenaTexas, United States1 39.21 January9.24.3×
Live OakTexas, United States1 28.11 January6.64.3×
HoustonTexas, United States2 45.31 January10.94.2×
SulphurLouisiana, United States1 27.431 December7.13.9×
KennerLouisiana, United States1 25.431 December6.63.8×

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 the United States

Number 116 of 130 episodes in the United States since our records began, by cities reached.

Bars: cities reached; colour: the level of the episode's highest daily reading. All 130.

Use this page

SmogRank, Texas and Louisiana, United States, December 2025 to January 2026: 8 cities with PM2.5 at twice their usual or more, 31 December 2025 to 1 January 2026, smogrank.com/episodes/2025-12-texas-and-louisiana-united-states (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.