SmogRank / Episodes / United States

Texas, United States, March 2025

For 1 day, on 4 March 2025, 11 cities in the United States had PM2.5 at least twice their usual for the time of year. The worst reading was Timberwood Park, Texas, United States: 34.6 µg/m³ on 4 March, about 4.6× its usual 7.6. Ended 4 March.

No cause namedWe have no fire or smoke records for these days, so we only say what the measurements show.
Cities reached11in 1 country
Days14 March 2025
Worst day4 March11 cities counted
Furthest above usual5.1×San Marcos

Day by day

4 March 11 cities at twice their usual or more
EdinburgLockhartMissionHeroica MatamorosAustinMission BendMissouri CityHoustonPasadenaGalvestonHighlandsBaytownConroeEagle PassCiudad General EscobedoMonterreyGarcíaSulphurPrienPort IsabelLaredoCorpus ChristiSan AntonioHelotesWindcrestLive OakTimberwood ParkLa PorteSeabrookSan Marcos
1 Mar234567
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

Timberwood ParkTimberwood Park, 1 March: 7.3 µg/m³Timberwood Park, 2 March: 6.2 µg/m³Timberwood Park, 3 March: 9.4 µg/m³Timberwood Park, 4 March: 34.6 µg/m³, 4.6× its usual 7.6Timberwood Park, 5 March: 13.0 µg/m³Timberwood Park, 6 March: 6.9 µg/m³Timberwood Park, 7 March: 16.0 µg/m³San MarcosSan Marcos, 1 March: 9.2 µg/m³San Marcos, 2 March: 7.1 µg/m³San Marcos, 3 March: 9.7 µg/m³San Marcos, 4 March: 34.4 µg/m³, 5.1× its usual 6.7San Marcos, 5 March: 9.9 µg/m³San Marcos, 6 March: 4.1 µg/m³San Marcos, 7 March: 12.7 µg/m³Live OakLive Oak, 1 March: 9.2 µg/m³Live Oak, 2 March: 7.3 µg/m³Live Oak, 3 March: 10.1 µg/m³Live Oak, 4 March: 34.3 µg/m³, 4.1× its usual 8.3Live Oak, 5 March: 12.7 µg/m³Live Oak, 6 March: 7.6 µg/m³Live Oak, 7 March: 15.4 µg/m³SeabrookSeabrook, 1 March: 17.2 µg/m³Seabrook, 2 March: 14.7 µg/m³Seabrook, 3 March: 16.9 µg/m³Seabrook, 4 March: 33.9 µg/m³, 5.1× its usual 6.6Seabrook, 5 March: 20.6 µg/m³Seabrook, 6 March: 3.0 µg/m³Seabrook, 7 March: 6.4 µg/m³La PorteLa Porte, 1 March: 17.2 µg/m³La Porte, 2 March: 14.7 µg/m³La Porte, 3 March: 16.9 µg/m³La Porte, 4 March: 33.9 µg/m³, 4.8× its usual 7.1La Porte, 5 March: 20.6 µg/m³La Porte, 6 March: 3.0 µg/m³La Porte, 7 March: 6.4 µg/m³WindcrestWindcrest, 1 March: 11.1 µg/m³Windcrest, 2 March: 8.4 µg/m³Windcrest, 3 March: 10.7 µg/m³Windcrest, 4 March: 33.9 µg/m³, 3.8× its usual 9.0Windcrest, 5 March: 12.4 µg/m³Windcrest, 6 March: 8.2 µg/m³Windcrest, 7 March: 14.8 µg/m³Corpus ChristiCorpus Christi, 1 March: 7.3 µg/m³Corpus Christi, 2 March: 5.9 µg/m³Corpus Christi, 3 March: 9.8 µg/m³Corpus Christi, 4 March: 31.0 µg/m³, 3.4× its usual 9.2Corpus Christi, 5 March: 24.2 µg/m³Corpus Christi, 6 March: 5.8 µg/m³Corpus Christi, 7 March: 14.2 µg/m³HelotesHelotes, 1 March: 11.4 µg/m³Helotes, 2 March: 9.0 µg/m³Helotes, 3 March: 11.8 µg/m³Helotes, 4 March: 30.8 µg/m³, 3.8× its usual 8.1Helotes, 5 March: 10.3 µg/m³Helotes, 6 March: 8.0 µg/m³Helotes, 7 March: 14.4 µg/m³San AntonioSan Antonio, 1 March: 10.4 µg/m³San Antonio, 2 March: 7.4 µg/m³San Antonio, 3 March: 10.3 µg/m³San Antonio, 4 March: 29.4 µg/m³, 3.5× its usual 8.3San Antonio, 5 March: 12.4 µg/m³San Antonio, 6 March: 8.0 µg/m³San Antonio, 7 March: 14.3 µg/m³Port IsabelPort Isabel, 1 March: no readingPort Isabel, 2 March: no readingPort Isabel, 3 March: no readingPort Isabel, 4 March: 28.9 µg/m³, 2.3× its usual 12.5Port Isabel, 5 March: 22.4 µg/m³Port Isabel, 6 March: 7.9 µg/m³Port Isabel, 7 March: 16.0 µg/m³LaredoLaredo, 1 March: 6.7 µg/m³Laredo, 2 March: 8.5 µg/m³Laredo, 3 March: 16.2 µg/m³Laredo, 4 March: 27.7 µg/m³, 2.9× its usual 9.7Laredo, 5 March: 17.2 µg/m³Laredo, 6 March: 19.3 µg/m³Laredo, 7 March: 17.3 µg/m³1 Mar234567
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 MarcosTexas, United States1 34.44 March6.75.1×
SeabrookTexas, United States1 33.94 March6.65.1×
La PorteTexas, United States1 33.94 March7.14.8×
Timberwood ParkTexas, United States1 34.64 March7.64.6×
Live OakTexas, United States1 34.34 March8.34.1×
WindcrestTexas, United States1 33.94 March9.03.8×
HelotesTexas, United States1 30.84 March8.13.8×
San AntonioTexas, United States1 29.44 March8.33.5×
Corpus ChristiTexas, United States1 31.04 March9.23.4×
LaredoTexas, United States1 27.74 March9.72.9×
Port IsabelTexas, United States1 28.94 March12.52.3×

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 112 of 151 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 151.

Use this page

SmogRank, Texas, United States, March 2025: 11 cities with PM2.5 at twice their usual or more, 4 March 2025, smogrank.com/episodes/2025-03-texas-united-states (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.