SmogRank / Thailand / Surin / Surin
Surin, month by month
Surin has a measured daily mean on 651 days since 5 January 2024. Its worst month was January 2026, at 103 US AQI (36.4 µg/m³), 139th of 2,978 cities on that month's world ranking. Its cleanest was September 2025, at 32 US AQI (5.8 µg/m³).
Every month since 2024
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
15 months
| Month | Why |
|---|---|
| Jul 2026 | 3 of 31 days measured; a month needs 22. The others: 27 with no readings from the monitor, 1 with readings for part of the day (a day needs 18 hours). |
| Nov 2025 | 12 of 30 days measured; a month needs 21. The others: 18 with no readings from the monitor. |
| Oct 2025 | 10 of 31 days measured; a month needs 22. The others: 21 with no readings from the monitor. |
| Aug 2025 | 6 of 31 days measured; a month needs 22. The others: 24 with no readings from the monitor, 1 with readings for part of the day (a day needs 18 hours). |
| Jul 2025 | No day measured. The others: 30 with no readings from the monitor, 1 with readings for part of the day (a day needs 18 hours). |
| Jan 2025 | 5 of 31 days measured; a month needs 22. The others: 26 with readings for part of the day (a day needs 18 hours). |
| 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 | 5 of 30 days measured; a month needs 21. The others: 25 with under 18 hours of readings or readings that failed our checks. |
| Aug 2024 | 15 of 31 days measured; a month needs 22. The others: 16 with under 18 hours of readings or readings that failed our checks. |
| Jul 2024 | 18 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks. |
| Mar 2024 | 20 of 31 days measured; a month needs 22. The others: 11 with under 18 hours of readings or readings that failed our checks. |
| Feb 2024 | 19 of 29 days measured; a month needs 21. The others: 1 missing from OpenAQ's archive, 9 with under 18 hours of readings or readings that failed our checks. |
| Jan 2024 | 21 of 31 days measured; a month needs 22. The others: 6 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.
Surin's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| January 2026 | 10336.4 µg/m³ | 139thof 2,978 | – |
| March 2025 | 10035.2 µg/m³ | 213thof 3,102 | Thailand and Laos, March 2025 |
| April 2024 | 9030.3 µg/m³ | 74thof 2,520 | Thailand and Laos, April and May 2024 |
| February 2025 | 8929.7 µg/m³ | 254thof 2,852 | – |
| February 2026 | 8627.8 µg/m³ | 311thof 3,180 | – |
| April 2026 | 8426.9 µg/m³ | 267thof 3,307 | – |
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.
Surin's worst days
| Day | US AQI | Episode |
|---|---|---|
| 25 Mar 2025 | 16473.6 µg/m³ | Thailand and Laos, March 2025 |
| 24 Mar 2025 | 16169.9 µg/m³ | Thailand and Laos, March 2025 |
| 12 Apr 2024 | 16068.3 µg/m³ | – |
| 25 Jan 2025 | 15967.1 µg/m³ | Northern Thailand, January 2025 |
| 26 Jan 2025 | 15966.4 µg/m³ | Northern Thailand, January 2025 |
| 23 Mar 2025 | 15865.2 µg/m³ | Thailand and Laos, March 2025 |
| 21 Jan 2026 | 15764.0 µg/m³ | – |
| 26 Mar 2025 | 15662.6 µg/m³ | Thailand and Laos, March 2025 |
| 13 Apr 2024 | 15459.6 µg/m³ | – |
| 3 Feb 2024 | 15359.0 µg/m³ | – |
Daily means, the highest since 5 Jan 2024; 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, Surin, Thailand, 5 Jan 2024 – 13 Oct 2026. Monitor data from Air4Thai via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/th/surin/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.
Surin now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-13 19:07 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).