SmogRank / Thailand / Uttaradit / Uttaradit

Uttaradit, month by month

Uttaradit has a measured daily mean on 738 days since 1 January 2023. Its worst month was April 2024, at 157 US AQI (64.5 µg/m³), 13th of 2,520 cities on that month's world ranking. Its cleanest was September 2025, at 51 US AQI (9.3 µg/m³).

Every month since 2023

202683 so far251 days measured236th of 2,791 in the world
Jan93#158Feb94#229Mar117#133Apr154#44May69#311Jun56#487Jul3 daysAug54#755Sep54#598Oct58#327
2025too few days for a mean (a year needs 256)221 days measured
Jan5 daysFeb107#121Mar133#94Apr88#182May61#440Jun59#598JulnoneAug6 daysSep51#824Oct10 daysNov12 daysDec80#374
2024too few days for a mean (a year needs 257)180 days measured
Jan99#93Feb122#47Mar18 daysApr157#13May85#76Jun55#435Jul13 daysAug11 daysSep5 daysOctnoneNov2 daysDecnone
2023too few days for a mean (a year needs 256)86 days measured
Jan102#39Feb2 daysMar9 daysApr19 daysMay15 daysJun10 daysJul3 daysAug3 daysSep3 daysOctnoneNovnoneDecnone
Each square is a month's mean PM2.5 in US AQI from Uttaradit's measured days, with its place on that month's world ranking under it. A month has a mean once 70% of its days are measured, the rule the monthly rankings use; under that, the square gives the days measured. Each square opens that month's ranking with Uttaradit marked; each year, the year's. A dashed square is the running month, so far.
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

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
MonthWhy
Jul 20263 of 31 days measured; a month needs 22. The others: 28 with under 18 hours of readings or readings that failed our checks.
Nov 202512 of 30 days measured; a month needs 21. The others: 18 with under 18 hours of readings or readings that failed our checks.
Oct 202510 of 31 days measured; a month needs 22. The others: 21 with under 18 hours of readings or readings that failed our checks.
Aug 20256 of 31 days measured; a month needs 22. The others: 25 with under 18 hours of readings or readings that failed our checks.
Jul 2025No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Jan 20255 of 31 days measured; a month needs 22. The others: 26 with under 18 hours of readings or readings that failed our checks.
Dec 2024No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Nov 20242 of 30 days measured; a month needs 21. The others: 28 with under 18 hours of readings or readings that failed our checks.
Oct 2024No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Sep 20245 of 30 days measured; a month needs 21. The others: 25 with under 18 hours of readings or readings that failed our checks.
Aug 202411 of 31 days measured; a month needs 22. The others: 20 with under 18 hours of readings or readings that failed our checks.
Jul 202413 of 31 days measured; a month needs 22. The others: 18 with under 18 hours of readings or readings that failed our checks.
Mar 202418 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks.
Dec 2023No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Nov 2023No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Oct 2023No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Sep 20233 of 30 days measured; a month needs 21. The others: 27 with under 18 hours of readings or readings that failed our checks.
Aug 20233 of 31 days measured; a month needs 22. The others: 28 with under 18 hours of readings or readings that failed our checks.
Jul 20233 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 202310 of 30 days measured; a month needs 21. The others: 20 with under 18 hours of readings or readings that failed our checks.
May 202315 of 31 days measured; a month needs 22. The others: 16 with under 18 hours of readings or readings that failed our checks.
Apr 202319 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 20239 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 20232 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.

Uttaradit's worst months

MonthUS AQIDays measuredWorld rankEpisode
April 2024 15764.5 µg/m³29 of 3013thof 2,520Thailand and Laos, April and May 2024
April 2026 15459.8 µg/m³30 of 3044thof 2,941–
March 2025 13348.4 µg/m³29 of 3194thof 2,862–
February 2024 12243.9 µg/m³22 of 2947thof 2,486–
March 2026 11741.8 µg/m³30 of 31133rdof 2,971–
February 2025 10737.9 µg/m³26 of 28121stof 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.

Uttaradit's worst days

DayUS AQIEpisode
2 May 2024 184103.0 µg/m³Thailand and Laos, April and May 2024
3 Apr 2024 17995.5 µg/m³–
2 Apr 2024 17893.8 µg/m³–
7 Apr 2023 17893.4 µg/m³–
8 Apr 2023 17792.9 µg/m³–
13 Apr 2026 17792.4 µg/m³–
7 Apr 2024 17488.8 µg/m³–
17 Apr 2023 17488.1 µg/m³–
23 Mar 2025 17285.0 µg/m³–
24 Mar 2025 17183.9 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, Uttaradit, Thailand, 1 Jan 2023 – 12 Oct 2026. Monitor data from Air4Thai via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/th/uttaradit/history (accessed 12 Oct 2026).

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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.

Uttaradit 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).