SmogRank / Thailand / Phrae / Phrae
Phrae, month by month
Phrae has a measured daily mean on 743 days since 1 January 2023. Its worst month was April 2026, at 166 US AQI (77.2 µg/m³), 19th of 2,941 cities on that month's world ranking. Its cleanest was September 2025, at 42 US AQI (7.5 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
26 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. |
| May 2025 | 21 of 31 days measured; a month needs 22. The others: 10 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 | 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 | 18 of 31 days measured; a month needs 22. The others: 13 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. |
| 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 | 4 of 31 days measured; a month needs 22. The others: 1 missing from OpenAQ's archive, 26 with under 18 hours of readings or readings that failed our checks. |
| Jun 2023 | 9 of 30 days measured; a month needs 21. The others: 21 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 | 17 of 30 days measured; a month needs 21. The others: 2 missing from OpenAQ's archive, 11 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. |
| Jan 2023 | 12 of 31 days measured; a month needs 22. The others: 6 missing from OpenAQ's archive, 13 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.
Phrae's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| April 2026 | 16677.2 µg/m³ | 19thof 2,941 | Northern Thailand and Laos, April 2026 Northern Thailand and Laos, March and April 2026 |
| March 2025 | 15459.1 µg/m³ | 46thof 2,862 | – |
| April 2024 | 15358.2 µg/m³ | 19thof 2,520 | Thailand and Laos, April and May 2024 |
| March 2026 | 14252.3 µg/m³ | 73rdof 2,971 | Northern Thailand and Laos, March and April 2026 |
| February 2024 | 14151.7 µg/m³ | 23rdof 2,486 | – |
| February 2025 | 12946.7 µg/m³ | 55thof 2,633 | – |
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.
Phrae's worst days
| Day | US AQI | Episode |
|---|---|---|
| 7 Apr 2023 | 210135.0 µg/m³ | Northern Thailand and Laos around Bangkok, 5 to 8 April 2023 |
| 7 Mar 2024 | 200125.0 µg/m³ | Northern Thailand and Laos, March 2024 |
| 27 Mar 2023 | 199124.0 µg/m³ | Northern Thailand and Laos, March and April 2023 |
| 2 Apr 2026 | 196120.0 µg/m³ | Northern Thailand and Laos, March and April 2026 |
| 1 Apr 2023 | 195118.0 µg/m³ | Northern Thailand and Laos, March and April 2023 |
| 3 Apr 2026 | 193116.0 µg/m³ | Northern Thailand and Laos, March and April 2026 |
| 5 Apr 2026 | 193116.0 µg/m³ | Northern Thailand and Laos, March and April 2026 |
| 5 Apr 2023 | 193115.0 µg/m³ | Northern Thailand and Laos around Bangkok, 5 to 8 April 2023 Northern Thailand and Laos around Chiang Mai, 5 April 2023 |
| 24 Mar 2025 | 193115.0 µg/m³ | – |
| 4 Apr 2026 | 192114.0 µg/m³ | Northern Thailand and Laos, March and April 2026 |
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, Phrae, Thailand, 1 Jan 2023 – 12 Oct 2026. Monitor data from Air4Thai via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/th/phrae/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.
Phrae now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 17:07 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).