SmogRank / Episodes / United States
Southern and eastern United States and Mexico, July and August 2024
For 3 days, from 31 July to 2 August 2024, 71 cities in the United States and Mexico had PM2.5 at least twice their usual for the time of year. The worst reading was Marion, Arkansas, United States: 46.6 µg/m³ on 1 August, about 3.7× its usual 12.5. Ended 2 August.
Day by day
How it spread
Every city it reached
| City | Days | Highest | Above usual |
|---|---|---|---|
| Timberwood ParkTexas, United States | 2 | 38.731 July | 4.6× |
| BartlettTennessee, United States | 2 | 45.41 August | 4.5× |
| San MarcosTexas, United States | 2 | 33.831 July | 4.3× |
| GeorgetownTexas, United States | 2 | 32.431 July | 4.3× |
| LockhartTexas, United States | 1 | 30.931 July | 4.3× |
| Fort SmithArkansas, United States | 1 | 33.91 August | 4.2× |
| BirminghamAlabama, United States | 2 | 37.52 August | 4.1× |
| HernandoMississippi, United States | 2 | 36.21 August | 4.1× |
| AdaOklahoma, United States | 2 | 34.71 August | 3.9× |
| Live OakTexas, United States | 2 | 36.331 July | 3.8× |
| DyersburgTennessee, United States | 1 | 30.61 August | 3.8× |
| BessemerAlabama, United States | 1 | 27.72 August | 3.8× |
| MarionArkansas, United States | 2 | 46.61 August | 3.7× |
| West MemphisArkansas, United States | 2 | 46.61 August | 3.7× |
| Corpus ChristiTexas, United States | 1 | 39.731 July | 3.7× |
| McAlesterOklahoma, United States | 1 | 36.01 August | 3.7× |
| LafayetteLouisiana, United States | 2 | 29.231 July | 3.7× |
| McDonoughGeorgia, United States | 1 | 27.42 August | 3.7× |
| Port IsabelTexas, United States | 1 | 43.431 July | 3.6× |
| MooreOklahoma, United States | 1 | 35.51 August | 3.6× |
| EdmondOklahoma, United States | 1 | 34.31 August | 3.6× |
| TaylorTexas, United States | 2 | 32.931 July | 3.6× |
| GainesvilleGeorgia, United States | 1 | 30.62 August | 3.6× |
| ClevelandMississippi, United States | 2 | 34.11 August | 3.5× |
| HelotesTexas, United States | 2 | 34.031 July | 3.5× |
| College StationTexas, United States | 2 | 31.831 July | 3.5× |
| LawrencevilleGeorgia, United States | 1 | 26.12 August | 3.5× |
| ColumbiaTennessee, United States | 1 | 25.01 August | 3.5× |
| ShreveportLouisiana, United States | 3 | 39.91 August | 3.4× |
| MissionTexas, United States | 1 | 37.831 July | 3.4× |
| AustinTexas, United States | 2 | 36.131 July | 3.4× |
| WindcrestTexas, United States | 2 | 33.931 July | 3.4× |
| LawtonOklahoma, United States | 1 | 29.51 August | 3.4× |
| FairviewGeorgia, United States | 1 | 28.92 August | 3.4× |
| East RidgeTennessee, United States | 1 | 28.92 August | 3.4× |
| Heroica MatamorosTamaulipas, Mexico | 1 | 32.831 July | 3.3× |
| Mission BendTexas, United States | 1 | 32.631 July | 3.3× |
| Oklahoma CityOklahoma, United States | 1 | 32.51 August | 3.3× |
| BeltonTexas, United States | 2 | 32.231 July | 3.3× |
| JacksonMississippi, United States | 1 | 31.61 August | 3.3× |
| JacksonTennessee, United States | 1 | 29.01 August | 3.3× |
| ChattanoogaTennessee, United States | 1 | 28.32 August | 3.3× |
| Little RockArkansas, United States | 2 | 38.81 August | 3.2× |
| Wells BranchTexas, United States | 2 | 35.431 July | 3.2× |
| EdinburgTexas, United States | 1 | 34.031 July | 3.2× |
| CorsicanaTexas, United States | 2 | 33.131 July | 3.2× |
| River OaksTexas, United States | 2 | 33.01 August | 3.2× |
| SaginawTexas, United States | 2 | 33.01 August | 3.2× |
| Port ArthurTexas, United States | 1 | 32.631 July | 3.2× |
| Eagle PassTexas, United States | 2 | 31.531 July | 3.2× |
| LaredoTexas, United States | 1 | 36.331 July | 3.1× |
| ConroeTexas, United States | 2 | 35.431 July | 3.1× |
| Fort WorthTexas, United States | 2 | 33.31 August | 3.1× |
| DentonTexas, United States | 2 | 32.81 August | 3.1× |
| KaufmanTexas, United States | 2 | 31.71 August | 3.1× |
| GlenpoolOklahoma, United States | 1 | 29.51 August | 3.1× |
| JenksOklahoma, United States | 1 | 29.51 August | 3.1× |
| La PorteTexas, United States | 1 | 29.231 July | 3.1× |
| SeabrookTexas, United States | 1 | 29.231 July | 3.1× |
| PasadenaTexas, United States | 1 | 32.531 July | 3.0× |
| Missouri CityTexas, United States | 1 | 31.931 July | 3.0× |
| GalvestonTexas, United States | 1 | 28.531 July | 3.0× |
| TexarkanaTexas, United States | 3 | 34.01 August | 2.8× |
| Baton RougeLouisiana, United States | 2 | 27.41 August | 2.8× |
| Phenix CityAlabama, United States | 1 | 25.42 August | 2.8× |
| SpringdaleArkansas, United States | 1 | 34.41 August | 2.7× |
| HoustonTexas, United States | 1 | 34.231 July | 2.7× |
| BaytownTexas, United States | 1 | 31.231 July | 2.6× |
| HighlandsTexas, United States | 1 | 31.231 July | 2.6× |
| TulsaOklahoma, United States | 1 | 28.01 August | 2.5× |
| Lacy-LakeviewTexas, United States | 1 | 26.31 August | 2.5× |
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 and Mexico
Number 20 of 163 episodes in the United States and Mexico since our records began, by cities reached.
- Eastern United States and Canada, June and July 2023343
- Northern United States and Canada, July 2026327
- United States and Canada, July 2023322
- Eastern United States and Canada, May and June 2023317
- North-eastern United States and Canada, 29 July to 9 August 2025292
- Northern United States and Canada, May and June 2025247
- United States and Canada, June 2023195
- North-western United States and Canada, August 2023176
- North-western United States and Canada, 4 to 22 August 2026151
- Northern United States and Canada, July 2025139
- Northern United States and Canada, June 2025134
- North-western United States and Canada, July and August 2026118
- Southern and eastern United States and Mexico, July and August 202471
Bars: cities reached; colour: the level of the episode's highest daily reading. All 163.
Use this page
SmogRank, Southern and eastern United States and Mexico, July and August 2024: 71 cities with PM2.5 at twice their usual or more, 31 July to 2 August 2024, smogrank.com/episodes/2024-07-southern-and-eastern-united-states-and-mexico (accessed 5 October 2026).
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.