SmogRank / Thailand / Bangkok / Khan Na Yao
Khan Na Yao, month by month
Khan Na Yao has a measured daily mean on 913 days since 1 January 2023. Its worst month was January 2025, at 140 US AQI (51.4 µg/m³), 32nd of 2,474 cities on that month's world ranking. Its cleanest was August 2024, at 60 US AQI (13.8 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
18 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. |
| Mar 2025 | 20 of 31 days measured; a month needs 22. The others: 11 with under 18 hours of readings or readings that failed our checks. |
| Apr 2024 | 19 of 30 days measured; a month needs 21. The others: 11 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 | 5 of 31 days measured; a month needs 22. The others: 1 missing from OpenAQ's archive, 25 with under 18 hours of readings or readings that failed our checks. |
| Jun 2023 | 7 of 30 days measured; a month needs 21. The others: 23 with under 18 hours of readings or readings that failed our checks. |
| May 2023 | 16 of 31 days measured; a month needs 22. The others: 15 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 | 8 of 31 days measured; a month needs 22. The others: 19 missing from OpenAQ's archive, 4 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.
Khan Na Yao's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| January 2025 | 14051.4 µg/m³ | 32ndof 2,474 | Northern Thailand, January 2025 |
| January 2024 | 12444.9 µg/m³ | 45thof 2,385 | – |
| February 2025 | 12043.1 µg/m³ | 68thof 2,633 | Thailand, 12 to 13 February 2025 |
| January 2026 | 11741.9 µg/m³ | 74thof 2,617 | – |
| January 2023 | 10235.8 µg/m³ | 41stof 1,261 | – |
| February 2026 | 9935.1 µg/m³ | 191stof 2,866 | – |
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.
Khan Na Yao's worst days
| Day | US AQI | Episode |
|---|---|---|
| 24 Jan 2025 | 185104.0 µg/m³ | Northern Thailand, January 2025 |
| 25 Jan 2025 | 17691.3 µg/m³ | Northern Thailand, January 2025 |
| 23 Jan 2025 | 17183.5 µg/m³ | Northern Thailand, January 2025 |
| 14 Feb 2024 | 16778.3 µg/m³ | Thailand, February 2024 |
| 13 Feb 2025 | 16677.1 µg/m³ | Thailand, 12 to 13 February 2025 |
| 1 Feb 2023 | 16676.7 µg/m³ | – |
| 28 Jan 2026 | 16372.5 µg/m³ | – |
| 15 Feb 2024 | 16271.9 µg/m³ | Thailand, February 2024 |
| 1 Feb 2025 | 16270.9 µg/m³ | – |
| 13 Feb 2024 | 16170.3 µg/m³ | Thailand, February 2024 |
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, Khan Na Yao, Thailand, 1 Jan 2023 – 12 Oct 2026. Monitor data from Air4Thai via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/th/khan-na-yao/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.
Khan Na Yao now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 18:07 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).