SmogRank / Thailand / Nakhon Pathom / Nakhon Pathom

Nakhon Pathom, month by month

Nakhon Pathom has a measured daily mean on 1,021 days since 1 January 2023. Its worst month was January 2026, at 125 US AQI (45.2 µg/m³), 61st of 2,617 cities on that month's world ranking. Its cleanest was August 2026, at 52 US AQI (9.9 µg/m³). 2024 averaged 75 US AQI (22.2 µg/m³), against 75 US AQI (22.1 µg/m³) in 2023.

Every month since 2023

202672 so far246 days measured350th of 2,793 in the world
2025too few days for a mean (a year needs 256)215 days measured
Jan5 daysFeb105#128Mar96#239Apr66#479May62#400Jun57#729JulnoneAug6 daysSep57#431Oct10 daysNov12 daysDec112#251
202475 for the year279 days measured91st of 2,097 in the world
202375 for the year281 days measured64th of 1,355 in the world
Each square is a month's mean PM2.5 in US AQI from Nakhon Pathom'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 Nakhon Pathom 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

12 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 20241 of 31 days measured; a month needs 22. The others: 30 with under 18 hours of readings or readings that failed our checks.
Nov 20243 of 30 days measured; a month needs 21. The others: 27 with under 18 hours of readings or readings that failed our checks.
Sep 202420 of 30 days measured; a month needs 21. The others: 10 with under 18 hours of readings or readings that failed our checks.
Sep 202320 of 30 days measured; a month needs 21. The others: 10 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.

Nakhon Pathom's worst months

MonthUS AQIDays measuredWorld rankEpisode
January 2026 12545.2 µg/m³28 of 3161stof 2,617–
January 2024 12244.2 µg/m³31 of 3148thof 2,385–
December 2025 11240.0 µg/m³22 of 31251stof 3,006–
February 2025 10537.3 µg/m³28 of 28128thof 2,633–
April 2023 10436.9 µg/m³26 of 3023rdof 1,622Thailand, April 2023
Northern Thailand and Laos around Bangkok, 5 to 8 April 2023
December 2023 10336.2 µg/m³30 of 3144thof 2,247–

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.

Nakhon Pathom's worst days

DayUS AQIEpisode
1 Feb 2023 16980.5 µg/m³Northern Thailand and Laos, January and February 2023
14 Feb 2024 16576.1 µg/m³Thailand, February 2024
21 Jan 2026 16474.2 µg/m³–
24 Jan 2025 16372.5 µg/m³–
15 Feb 2024 16271.2 µg/m³Thailand, February 2024
23 Mar 2025 16068.6 µg/m³Thailand and Laos, March 2025
15 Jan 2026 15967.3 µg/m³–
20 Jan 2026 15966.7 µg/m³–
24 Mar 2025 15966.5 µg/m³Thailand and Laos, March 2025
13 Feb 2024 15763.7 µg/m³Thailand, 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, Nakhon Pathom, Thailand, 1 Jan 2023 – 12 Oct 2026. Monitor data from Air4Thai via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/th/nakhon-pathom/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.

Nakhon Pathom now: the last 24 hours, its ranks today and the last 12 months day by day.

Updated 2026-10-12 23:07 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).