SmogRank / Mexico / Baja California / Mexicali

Mexicali, month by month

Mexicali has a measured daily mean on 811 days since 10 January 2023. Its worst month was December 2025, at 107 US AQI (38.1 µg/m³), 260th of 3,006 cities on that month's world ranking. Its cleanest was July 2025, at 58 US AQI (13.0 µg/m³).

Every month since 2023

202675 so far281 days measured317th of 2,791 in the world
Jan77#304Feb80#382Mar80#437Apr64#516May71#279Jun68#268Jul73#308Aug89#120Sep80#180Oct67#142
202569 for the year284 days measured259th of 2,681 in the world
JannoneFeb3 daysMar70#603Apr64#509May62#400Jun71#228Jul58#639Aug63#332Sep17 daysOct64#330Nov76#341Dec107#260
2024too few days for a mean (a year needs 257)32 days measured
Jan15 daysFeb1 dayMar4 daysApr2 daysMay1 dayJun5 daysJulnoneAug2 daysSep1 dayOct1 dayNovnoneDecnone
2023too few days for a mean (a year needs 256)214 days measured
Jan14 daysFeb1 dayMar10 daysApr96#33May4 daysJun7 daysJul19 daysAug94#50Sep85#45Oct17 daysNov85#35Dec88#70
Each square is a month's mean PM2.5 in US AQI from Mexicali'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 Mexicali 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

22 months
MonthWhy
Sep 202517 of 30 days measured; a month needs 21. The others: 13 with under 18 hours of readings or readings that failed our checks.
Feb 20253 of 28 days measured; a month needs 20. The others: 25 with under 18 hours of readings or readings that failed our checks.
Jan 2025No day measured. The others: 31 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 2024No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Oct 20241 of 31 days measured; a month needs 22. The others: 30 with under 18 hours of readings or readings that failed our checks.
Sep 20241 of 30 days measured; a month needs 21. The others: 29 with under 18 hours of readings or readings that failed our checks.
Aug 20242 of 31 days measured; a month needs 22. The others: 29 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 20245 of 30 days measured; a month needs 21. The others: 25 with under 18 hours of readings or readings that failed our checks.
May 20241 of 31 days measured; a month needs 22. The others: 30 with under 18 hours of readings or readings that failed our checks.
Apr 20242 of 30 days measured; a month needs 21. The others: 28 with under 18 hours of readings or readings that failed our checks.
Mar 20244 of 31 days measured; a month needs 22. The others: 27 with under 18 hours of readings or readings that failed our checks.
Feb 20241 of 29 days measured; a month needs 21. The others: 1 missing from OpenAQ's archive, 27 with under 18 hours of readings or readings that failed our checks.
Jan 202415 of 31 days measured; a month needs 22. The others: 16 with under 18 hours of readings or readings that failed our checks.
Oct 202317 of 31 days measured; a month needs 22. The others: 14 with under 18 hours of readings or readings that failed our checks.
Jul 202319 of 31 days measured; a month needs 22. The others: 1 missing from OpenAQ's archive, 11 with under 18 hours of readings or readings that failed our checks.
Jun 20237 of 30 days measured; a month needs 21. The others: 23 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 202310 of 31 days measured; a month needs 22. The others: 20 missing from OpenAQ's archive, 1 with under 18 hours of readings or readings that failed our checks.
Feb 20231 of 28 days measured; a month needs 20. The others: 25 missing from OpenAQ's archive, 2 with under 18 hours of readings or readings that failed our checks.
Jan 202314 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.

Mexicali's worst months

MonthUS AQIDays measuredWorld rankEpisode
December 2025 10738.1 µg/m³31 of 31260thof 3,006Western United States and Mexico, December 2025
April 2023 9633.2 µg/m³26 of 3033rdof 1,622–
August 2023 9432.1 µg/m³25 of 3150thof 1,980–
August 2026 8929.4 µg/m³31 of 31120thof 2,896–
December 2023 8828.9 µg/m³31 of 3170thof 2,247–
September 2023 8527.6 µg/m³30 of 3045thof 2,176–

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.

Mexicali's worst days

DayUS AQIEpisode
7 Aug 2023 187106.4 µg/m³–
29 Aug 2026 17082.6 µg/m³–
16 Dec 2025 16676.3 µg/m³Western United States and Mexico, December 2025
6 Dec 2025 16575.5 µg/m³–
31 Jul 2023 16067.7 µg/m³–
17 Dec 2025 15967.3 µg/m³Western United States and Mexico, December 2025
2 Aug 2023 15966.9 µg/m³–
12 Jun 2025 15864.9 µg/m³–
11 Dec 2025 15764.3 µg/m³–
6 Nov 2023 15663.3 µg/m³–

Daily means, the highest since 10 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, Mexicali, Mexico, 10 Jan 2023 – 11 Oct 2026. Monitor data from Sinaica Mexico via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/mx/mexicali/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.

Mexicali 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).