SmogRank / United States / Texas / Port Arthur
Port Arthur, month by month
Port Arthur has a measured daily mean on 1,116 days since 1 January 2023. Its worst month was July 2024, at 60 US AQI (14.1 µg/m³), 221st of 2,566 cities on that month's world ranking. Its cleanest was March 2026, at 36 US AQI (6.5 µg/m³). 2025 averaged 50 US AQI (9.0 µg/m³), against 54 US AQI (10.8 µg/m³) in 2024.
Every month since 2023
The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales
Months without a mean, and why
10 months
| Month | Why |
|---|---|
| Sep 2026 | 18 of 30 days measured; a month needs 21. The others: 6 with no readings from the monitor, 6 with readings for part of the day (a day needs 18 hours). |
| Aug 2026 | 18 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks. |
| Jan 2026 | 20 of 31 days measured; a month needs 22. The others: 11 with under 18 hours of readings or readings that failed our checks. |
| Dec 2025 | 17 of 31 days measured; a month needs 22. The others: 14 with under 18 hours of readings or readings that failed our checks. |
| Mar 2025 | 16 of 31 days measured; a month needs 22. The others: 15 with under 18 hours of readings or readings that failed our checks. |
| Feb 2025 | 16 of 28 days measured; a month needs 20. The others: 12 with under 18 hours of readings or readings that failed our checks. |
| Apr 2024 | 14 of 30 days measured; a month needs 21. The others: 16 with under 18 hours of readings or readings that failed our checks. |
| Dec 2023 | 20 of 31 days measured; a month needs 22. The others: 11 with under 18 hours of readings or readings that failed our checks. |
| Mar 2023 | 10 of 31 days measured; a month needs 22. The others: 20 missing from OpenAQ's archive, 1 with under 18 hours of readings or readings that failed our checks. |
| Feb 2023 | 2 of 28 days measured; a month needs 20. The others: 25 missing from OpenAQ's archive, 1 with under 18 hours of readings or readings that failed our checks. |
A day counts once 18 hours of it are measured; a month needs 70% of its days.
Port Arthur's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| July 2024 | 6014.1 µg/m³ | 221stof 2,566 | Southern and eastern United States and Mexico, July and August 2024 |
| July 2023 | 6013.9 µg/m³ | 209thof 1,432 | – |
| May 2024 | 6013.7 µg/m³ | 352ndof 2,684 | Southern United States and Mexico, 7 to 10 May 2024 |
| May 2023 | 5913.4 µg/m³ | 192ndof 1,600 | Southern United States, May 2023 |
| April 2026 | 5813.0 µg/m³ | 670thof 2,941 | Southern United States and Mexico, April 2026 |
| October 2024 | 5812.7 µg/m³ | 351stof 2,020 | – |
Monthly means over the days measured; finished months only. World rank: its place on that month's world ranking of every city with enough days. Each month opens that ranking.
Port Arthur's worst days
| Day | US AQI | Episode |
|---|---|---|
| 9 May 2024 | 10738.1 µg/m³ | Southern United States and Mexico, 7 to 10 May 2024 |
| 17 Feb 2025 | 10135.5 µg/m³ | – |
| 31 Jul 2024 | 9532.6 µg/m³ | Southern and eastern United States and Mexico, July and August 2024 |
| 28 Apr 2026 | 8628.0 µg/m³ | Southern United States and Mexico, April 2026 |
| 29 Apr 2026 | 8627.8 µg/m³ | – |
| 22 Apr 2026 | 8527.5 µg/m³ | – |
| 26 May 2023 | 8527.1 µg/m³ | – |
| 27 Apr 2026 | 8527.1 µg/m³ | Southern United States and Mexico, April 2026 |
| 24 Apr 2026 | 8225.8 µg/m³ | – |
| 8 Feb 2025 | 8225.6 µg/m³ | – |
Daily means, the highest since 1 Jan 2023; the WHO's daily guideline is 15 µg/m³. Each date opens that day's world ranking, and each episode the bad-air spell it was part of.
Use this history
SmogRank, PM2.5 monthly and daily means, Port Arthur, United States, 1 Jan 2023 – 11 Oct 2026. Monitor data from AirNow, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/us/port-arthur/history (accessed 13 Oct 2026).
You're welcome to reuse a single chart, image or figure with this citation and a link. Terms. Raw monitor readings in bulk are published by OpenAQ, under each provider's licence.
Port Arthur now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-13 03:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index. Some low-cost readings: Sensor.Community, ODbL (data and licence). Some readings: Uzhydromet (Uzbekistan's Hydrometeorological Service); Department of Environment, Nepal; Vietnam's government monitors; Aurassure; Umhverfisstofnun (Environment Agency of Iceland); RMCAB (Secretaría Distrital de Ambiente, Bogotá); Love My Air (City and County of Denver), no reuse terms published (why we use them).