SmogRank / Mexico / México / Ciudad Nezahualcoyotl

Ciudad Nezahualcoyotl, month by month

Ciudad Nezahualcoyotl has a measured daily mean on 570 days since 8 January 2023. Its worst month was April 2025, at 90 US AQI (30.0 µg/m³), 166th of 2,951 cities on that month's world ranking. Its cleanest was June 2026, at 64 US AQI (16.3 µg/m³).

Every month since 2023

202674 so far217 days measured325th of 2,798 in the world
Jan18 daysFeb1 dayMar18 daysApr75#371May82#212Jun64#299Jul74#284Aug73#225Sep68#303Oct59#312
2025too few days for a mean (a year needs 256)195 days measured
Jan83#135Feb11 daysMar89#310Apr90#166May80#201Jun18 daysJul2 daysAugnoneSep1 dayOct1 dayNov88#258Dec90#311
2024too few days for a mean (a year needs 257)45 days measured
JannoneFebnoneMarnoneAprnoneMaynoneJunnoneJulnoneAugnoneSepnoneOct9 daysNov16 daysDec20 days
2023too few days for a mean (a year needs 256)113 days measured
Jan16 daysFeb2 daysMar11 daysApr82#74May4 daysJun1 dayJul7 daysAug21 daysSep69#112OctnoneNovnoneDecnone
Each square is a month's mean PM2.5 in US AQI from Ciudad Nezahualcoyotl'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 Ciudad Nezahualcoyotl marked; each year, the year's. A dashed square is the running month, so far.
Good0–50
Moderate51–100
Unhealthy for 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

31 months
MonthWhy
Mar 202618 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks.
Feb 20261 of 28 days measured; a month needs 20. The others: 27 with under 18 hours of readings or readings that failed our checks.
Jan 202618 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks.
Oct 20251 of 31 days measured; a month needs 22. The others: 30 with under 18 hours of readings or readings that failed our checks.
Sep 20251 of 30 days measured; a month needs 21. The others: 29 with under 18 hours of readings or readings that failed our checks.
Aug 2025No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Jul 20252 of 31 days measured; a month needs 22. The others: 29 with under 18 hours of readings or readings that failed our checks.
Jun 202518 of 30 days measured; a month needs 21. The others: 12 with under 18 hours of readings or readings that failed our checks.
Feb 202511 of 28 days measured; a month needs 20. The others: 17 with under 18 hours of readings or readings that failed our checks.
Dec 202420 of 31 days measured; a month needs 22. The others: 11 with under 18 hours of readings or readings that failed our checks.
Nov 202416 of 30 days measured; a month needs 21. The others: 14 with under 18 hours of readings or readings that failed our checks.
Oct 20249 of 31 days measured; a month needs 22. The others: 22 with under 18 hours of readings or readings that failed our checks.
Sep 2024No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Aug 2024No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Jul 2024No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Jun 2024No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
May 2024No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Apr 2024No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Mar 2024No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Feb 2024No day measured. The others: 1 missing from OpenAQ's archive, 28 with under 18 hours of readings or readings that failed our checks.
Jan 2024No day measured. The others: 31 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.
Aug 202321 of 31 days measured; a month needs 22. The others: 10 with under 18 hours of readings or readings that failed our checks.
Jul 20237 of 31 days measured; a month needs 22. The others: 1 missing from OpenAQ's archive, 23 with under 18 hours of readings or readings that failed our checks.
Jun 20231 of 30 days measured; a month needs 21. The others: 29 with under 18 hours of readings or readings that failed our checks.
May 20234 of 31 days measured; a month needs 22. The others: 27 with under 18 hours of readings or readings that failed our checks.
Mar 202311 of 31 days measured; a month needs 22. The others: 20 missing from OpenAQ's archive.
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.
Jan 202316 of 31 days measured; a month needs 22. The others: 6 missing from OpenAQ's archive, 2 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.

Ciudad Nezahualcoyotl's worst months

MonthUS AQIDays measuredWorld rank
April 2025 9030.0 µg/m³30 of 30166thof 2,951
December 2025 9030.0 µg/m³31 of 31311thof 3,006
March 2025 8929.3 µg/m³23 of 31310thof 2,862
November 2025 8829.2 µg/m³30 of 30258thof 2,715
January 2025 8326.5 µg/m³26 of 31135thof 2,474
April 2023 8225.9 µg/m³26 of 3074thof 1,622

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.

Ciudad Nezahualcoyotl's worst days

DayUS AQIEpisode
1 Jan 2026 207132.0 µg/m³Southern Mexico, January 2026
1 Jan 2025 187107.0 µg/m³–
25 Dec 2024 16778.0 µg/m³Guanajuato, México and Mexico City, Mexico, December 2024
30 Apr 2025 16271.4 µg/m³–
25 Dec 2025 14151.7 µg/m³–
20 Jan 2023 14051.2 µg/m³–
16 Sept 2023 13549.2 µg/m³–
18 Apr 2025 13147.8 µg/m³–
1 Jul 2026 13147.5 µg/m³–
6 Jan 2026 13047.2 µg/m³–

Daily means, the highest since 8 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, Ciudad Nezahualcoyotl, Mexico, 8 Jan 2023 – 11 Oct 2026. Monitor data from Sinaica Mexico via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/mx/ciudad-nezahualcoyotl/history (accessed 13 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.

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

Updated 2026-10-13 04:07 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).