SmogRank / Thailand / Ubon Ratchathani / Ubon Ratchathani
Ubon Ratchathani, month by month
Ubon Ratchathani has a measured daily mean on 738 days since 1 January 2023. Its worst month was April 2024, at 162 US AQI (71.8 µg/m³), 9th of 2,520 cities on that month's world ranking. Its cleanest was September 2025, at 34 US AQI (6.2 µg/m³).
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
24 months
| Month | Why |
|---|---|
| Jul 2026 | 3 of 31 days measured; a month needs 22. The others: 28 with under 18 hours of readings or readings that failed our checks. |
| Nov 2025 | 12 of 30 days measured; a month needs 21. The others: 18 with under 18 hours of readings or readings that failed our checks. |
| Oct 2025 | 10 of 31 days measured; a month needs 22. The others: 21 with under 18 hours of readings or readings that failed our checks. |
| Aug 2025 | 6 of 31 days measured; a month needs 22. The others: 25 with under 18 hours of readings or readings that failed our checks. |
| Jul 2025 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Jan 2025 | 5 of 31 days measured; a month needs 22. The others: 26 with under 18 hours of readings or readings that failed our checks. |
| Dec 2024 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Nov 2024 | 3 of 30 days measured; a month needs 21. The others: 27 with under 18 hours of readings or readings that failed our checks. |
| Oct 2024 | 2 of 31 days measured; a month needs 22. The others: 29 with under 18 hours of readings or readings that failed our checks. |
| Sep 2024 | 4 of 30 days measured; a month needs 21. The others: 26 with under 18 hours of readings or readings that failed our checks. |
| Aug 2024 | 16 of 31 days measured; a month needs 22. The others: 15 with under 18 hours of readings or readings that failed our checks. |
| Jul 2024 | 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 2024 | 19 of 31 days measured; a month needs 22. The others: 12 with under 18 hours of readings or readings that failed our checks. |
| Dec 2023 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Nov 2023 | No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks. |
| Oct 2023 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Sep 2023 | 3 of 30 days measured; a month needs 21. The others: 27 with under 18 hours of readings or readings that failed our checks. |
| Aug 2023 | 3 of 31 days measured; a month needs 22. The others: 28 with under 18 hours of readings or readings that failed our checks. |
| Jul 2023 | 3 of 31 days measured; a month needs 22. The others: 1 missing from OpenAQ's archive, 27 with under 18 hours of readings or readings that failed our checks. |
| Jun 2023 | 10 of 30 days measured; a month needs 21. The others: 20 with under 18 hours of readings or readings that failed our checks. |
| May 2023 | 15 of 31 days measured; a month needs 22. The others: 16 with under 18 hours of readings or readings that failed our checks. |
| Apr 2023 | 19 of 30 days measured; a month needs 21. The others: 2 missing from OpenAQ's archive, 9 with under 18 hours of readings or readings that failed our checks. |
| Mar 2023 | 9 of 31 days measured; a month needs 22. The others: 19 missing from OpenAQ's archive, 3 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.
Ubon Ratchathani's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| April 2024 | 16271.8 µg/m³ | 9thof 2,520 | Thailand and Laos, April and May 2024 |
| March 2025 | 15459.4 µg/m³ | 45thof 2,862 | Thailand and Laos, March 2025 |
| April 2025 | 15358.1 µg/m³ | 20thof 2,951 | – |
| April 2026 | 15055.4 µg/m³ | 56thof 2,941 | – |
| February 2024 | 14653.8 µg/m³ | 20thof 2,486 | Thailand, February 2024 Northern Thailand and Laos, February 2024and 1 more |
| May 2024 | 10838.3 µg/m³ | 46thof 2,684 | Thailand and Laos, April and May 2024 |
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.
Ubon Ratchathani's worst days
| Day | US AQI | Episode |
|---|---|---|
| 26 Mar 2025 | 208133.0 µg/m³ | Thailand and Laos, March 2025 |
| 27 Mar 2025 | 201126.0 µg/m³ | Thailand and Laos, March 2025 |
| 3 May 2024 | 191112.0 µg/m³ | Thailand and Laos, April and May 2024 |
| 29 Mar 2025 | 191112.0 µg/m³ | Thailand and Laos, March 2025 |
| 2 May 2024 | 189110.0 µg/m³ | Thailand and Laos, April and May 2024 |
| 25 Mar 2025 | 189109.0 µg/m³ | Thailand and Laos, March 2025 |
| 28 Mar 2025 | 189109.0 µg/m³ | Thailand and Laos, March 2025 |
| 21 Apr 2025 | 188108.0 µg/m³ | – |
| 13 Apr 2024 | 184102.0 µg/m³ | – |
| 14 Apr 2024 | 18096.4 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, Ubon Ratchathani, Thailand, 1 Jan 2023 – 12 Oct 2026. Monitor data from Air4Thai via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/th/ubon-ratchathani/history (accessed 12 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.
Ubon Ratchathani now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 22:07 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).