SmogRank / Mexico / Coahuila / Saltillo

Saltillo, month by month

Saltillo has a measured daily mean on 523 days since 24 March 2023. Its worst month was December 2023, at 72 US AQI (20.3 µg/m³), 158th of 2,247 cities on that month's world ranking. Its cleanest was June 2025, at 62 US AQI (14.9 µg/m³).

Every month since 2023

2026too few days for a mean (a year needs 199)170 days measured
Jan13 daysFeb70#587Mar11 daysApr15 daysMay69#311Jun18 daysJul18 daysAug18 daysSep66#318Oct59#299
2025too few days for a mean (a year needs 256)193 days measured
Jan1 dayFeb5 daysMar11 daysApr69#405May17 daysJun62#452Jul72#200Aug10 daysSep13 daysOct71#290Nov18 daysDec21 days
2024too few days for a mean (a year needs 257)19 days measured
JannoneFebnoneMarnoneApr4 daysMay4 daysJun7 daysJulnoneAugnoneSep1 dayOctnoneNov1 dayDec2 days
2023too few days for a mean (a year needs 256)141 days measured
JanFebMar6 daysApr12 daysMay4 daysJun3 daysJul10 daysAug15 daysSep68#121Oct14 daysNov66#113Dec72#158
Each square is a month's mean PM2.5 in US AQI from Saltillo'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 Saltillo 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

33 months
MonthWhy
Aug 202618 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks.
Jul 202618 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks.
Jun 202618 of 30 days measured; a month needs 21. The others: 12 with under 18 hours of readings or readings that failed our checks.
Apr 202615 of 30 days measured; a month needs 21. The others: 15 with under 18 hours of readings or readings that failed our checks.
Mar 202611 of 31 days measured; a month needs 22. The others: 20 with under 18 hours of readings or readings that failed our checks.
Jan 202613 of 31 days measured; a month needs 22. The others: 18 with under 18 hours of readings or readings that failed our checks.
Dec 202521 of 31 days measured; a month needs 22. The others: 10 with under 18 hours of readings or readings that failed our checks.
Nov 202518 of 30 days measured; a month needs 21. The others: 12 with under 18 hours of readings or readings that failed our checks.
Sep 202513 of 30 days measured; a month needs 21. The others: 17 with under 18 hours of readings or readings that failed our checks.
Aug 202510 of 31 days measured; a month needs 22. The others: 21 with under 18 hours of readings or readings that failed our checks.
May 202517 of 31 days measured; a month needs 22. The others: 14 with under 18 hours of readings or readings that failed our checks.
Mar 202511 of 31 days measured; a month needs 22. The others: 20 with under 18 hours of readings or readings that failed our checks.
Feb 20255 of 28 days measured; a month needs 20. The others: 23 with under 18 hours of readings or readings that failed our checks.
Jan 20251 of 31 days measured; a month needs 22. The others: 30 with under 18 hours of readings or readings that failed our checks.
Dec 20242 of 31 days measured; a month needs 22. The others: 29 with under 18 hours of readings or readings that failed our checks.
Nov 20241 of 30 days measured; a month needs 21. The others: 29 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 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 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 20247 of 30 days measured; a month needs 21. The others: 23 with under 18 hours of readings or readings that failed our checks.
May 20244 of 31 days measured; a month needs 22. The others: 27 with under 18 hours of readings or readings that failed our checks.
Apr 20244 of 30 days measured; a month needs 21. The others: 26 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.
Oct 202314 of 31 days measured; a month needs 22. The others: 17 with under 18 hours of readings or readings that failed our checks.
Aug 202315 of 31 days measured; a month needs 22. The others: 16 with under 18 hours of readings or readings that failed our checks.
Jul 202310 of 31 days measured; a month needs 22. The others: 1 missing from OpenAQ's archive, 20 with under 18 hours of readings or readings that failed our checks.
Jun 20233 of 30 days measured; a month needs 21. The others: 27 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.
Apr 202312 of 30 days measured; a month needs 21. The others: 3 missing from OpenAQ's archive, 15 with under 18 hours of readings or readings that failed our checks.
Mar 20236 of 31 days measured; a month needs 22. The others: 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.

Saltillo's worst months

MonthUS AQIDays measuredWorld rankEpisode
December 2023 7220.3 µg/m³23 of 31158thof 2,247–
July 2025 7220.2 µg/m³28 of 31200thof 2,889–
October 2025 7119.7 µg/m³25 of 31290thof 2,614–
February 2026 7019.1 µg/m³21 of 28587thof 2,866–
May 2026 6918.7 µg/m³25 of 31311thof 2,874–
April 2025 6918.6 µg/m³21 of 30405thof 2,951Southern United States and Mexico, March and April 2025

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.

Saltillo's worst days

DayUS AQIEpisode
9 Aug 2026 306228.0 µg/m³–
22 Jul 2025 224149.0 µg/m³–
19 Aug 2025 201126.0 µg/m³–
19 Apr 2024 191112.0 µg/m³–
31 Mar 2025 190111.0 µg/m³Southern United States and Mexico, March and April 2025
18 Dec 2025 190111.0 µg/m³–
15 Dec 2025 18299.9 µg/m³–
3 Sept 2024 17894.5 µg/m³–
15 Feb 2025 17691.1 µg/m³–
26 Mar 2025 17488.8 µg/m³–

Daily means, the highest since 24 Mar 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, Saltillo, Mexico, 24 Mar 2023 – 11 Oct 2026. Monitor data from Sinaica Mexico via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/mx/saltillo/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.

Saltillo 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).