SmogRank / Mexico / San Luis Potosí

Air quality in San Luis Potosí

San Luis Potosí, Mexico. PM2.5 from 1 reference monitor, updated hourly.

35.0µg/m³
Moderate

Latest hour (23:00 UTC), 2.3× the WHO 24-hour guideline. 24-hour average 34.3 µg/m³.

Rank among 1,324 cities

24 hours#23of 1,324, at 34.3 µg/m³
7 days#47of 2,298, at 34.0 µg/m³
30 days#79of 2,311, at 31.7 µg/m³
This year#175of 2,176, at 25.7 µg/m³

Why it ranks here

Worse than usual today. The last 24 hours averaged 34.3 µg/m³, about 3.5× its usual for this time of year (9.9). A jump like this usually has a short-lived cause: likely smoke from fires, dust, or still weather trapping local emissions.
Seasonal. Over the past year its worst months were January, February, April, May, July, August, September, averaging up to 32.0 µg/m³ against 10.2 in its cleanest month. Seasonal peaks usually come from heating, crop burning, fire or dust seasons.

Based on San Luis Potosí's own measurements; causes are the usual kinds for a pattern like this, not a confirmed source.

The last 12 months, day by day

1102031Oct 2025NovDecJan 2026FebMarAprMayJunJulAugSep2025-10-01: 12.4 µg/m³2025-10-02: 11.8 µg/m³2025-10-03: 8.7 µg/m³2025-10-04: 11.3 µg/m³2025-10-05: 15.4 µg/m³2025-10-06: 10.9 µg/m³2025-10-07: 9.6 µg/m³2025-10-08: 2.6 µg/m³2025-10-09: 2.1 µg/m³2025-10-10: 2.1 µg/m³2025-10-11: 5.2 µg/m³2025-10-12: 14.7 µg/m³2025-10-13: 11.2 µg/m³2025-10-14: 8.1 µg/m³2025-10-15: 11.8 µg/m³2025-10-16: 11.9 µg/m³2025-10-17: 17.5 µg/m³2025-10-18: 20.8 µg/m³2025-10-19: 11.8 µg/m³2025-10-20: 12.6 µg/m³2025-10-21: no data2025-10-22: no data2025-10-23: no data2025-10-24: no data2025-10-25: no data2025-10-26: no data2025-10-27: no data2025-10-28: no data2025-10-29: no data2025-10-30: no data2025-10-31: no data2025-11-01: no data2025-11-02: no data2025-11-03: no data2025-11-04: no data2025-11-05: no data2025-11-06: no data2025-11-07: no data2025-11-08: no data2025-11-09: no data2025-11-10: no data2025-11-11: no data2025-11-12: no data2025-11-13: no data2025-11-14: no data2025-11-15: no data2025-11-16: no data2025-11-17: no data2025-11-18: no data2025-11-19: no data2025-11-20: no data2025-11-21: no data2025-11-22: no data2025-11-23: no data2025-11-24: no data2025-11-25: no data2025-11-26: no data2025-11-27: no data2025-11-28: no data2025-11-29: no data2025-11-30: no data2025-12-01: no data2025-12-02: 36.5 µg/m³2025-12-03: 31.5 µg/m³2025-12-04: 28.8 µg/m³2025-12-05: 8.5 µg/m³2025-12-06: 1.0 µg/m³2025-12-07: 1.0 µg/m³2025-12-08: 1.0 µg/m³2025-12-09: 1.0 µg/m³2025-12-10: 1.0 µg/m³2025-12-11: 1.0 µg/m³2025-12-12: 1.0 µg/m³2025-12-13: 1.0 µg/m³2025-12-14: 1.0 µg/m³2025-12-15: 1.0 µg/m³2025-12-16: 10.1 µg/m³2025-12-17: 27.4 µg/m³2025-12-18: 27.9 µg/m³2025-12-19: 27.9 µg/m³2025-12-20: 36.3 µg/m³2025-12-21: 26.3 µg/m³2025-12-22: 25.6 µg/m³2025-12-23: 24.8 µg/m³2025-12-24: 22.5 µg/m³2025-12-25: 30.5 µg/m³2025-12-26: 21.9 µg/m³2025-12-27: 25.5 µg/m³2025-12-28: 28.1 µg/m³2025-12-29: 26.4 µg/m³2025-12-30: 20.7 µg/m³2025-12-31: 35.0 µg/m³2026-01-01: 84.0 µg/m³2026-01-02: 30.1 µg/m³2026-01-03: 32.0 µg/m³2026-01-04: 28.3 µg/m³2026-01-05: 36.7 µg/m³2026-01-06: 36.0 µg/m³2026-01-07: 35.4 µg/m³2026-01-08: 32.9 µg/m³2026-01-09: 30.8 µg/m³2026-01-10: 39.4 µg/m³2026-01-11: 15.8 µg/m³2026-01-12: 1.0 µg/m³2026-01-13: 1.0 µg/m³2026-01-14: 11.3 µg/m³2026-01-15: 22.6 µg/m³2026-01-16: 38.1 µg/m³2026-01-17: 24.2 µg/m³2026-01-18: 29.3 µg/m³2026-01-19: 30.7 µg/m³2026-01-20: 24.8 µg/m³2026-01-21: 30.8 µg/m³2026-01-22: 33.3 µg/m³2026-01-23: 31.4 µg/m³2026-01-24: 21.0 µg/m³2026-01-25: 19.5 µg/m³2026-01-26: 23.0 µg/m³2026-01-27: 30.4 µg/m³2026-01-28: 26.8 µg/m³2026-01-29: 32.3 µg/m³2026-01-30: 29.1 µg/m³2026-01-31: 22.2 µg/m³2026-02-01: 24.8 µg/m³2026-02-02: 30.0 µg/m³2026-02-03: 29.8 µg/m³2026-02-04: 34.8 µg/m³2026-02-05: 22.6 µg/m³2026-02-06: 36.3 µg/m³2026-02-07: 29.8 µg/m³2026-02-08: 24.8 µg/m³2026-02-09: 27.3 µg/m³2026-02-10: 29.9 µg/m³2026-02-11: 28.8 µg/m³2026-02-12: 38.9 µg/m³2026-02-13: 39.5 µg/m³2026-02-14: 29.9 µg/m³2026-02-15: 25.7 µg/m³2026-02-16: 34.5 µg/m³2026-02-17: 35.4 µg/m³2026-02-18: 43.5 µg/m³2026-02-19: 25.0 µg/m³2026-02-20: 27.4 µg/m³2026-02-21: 25.1 µg/m³2026-02-22: 27.1 µg/m³2026-02-23: 28.0 µg/m³2026-02-24: 32.2 µg/m³2026-02-25: 33.9 µg/m³2026-02-26: 31.5 µg/m³2026-02-27: 22.6 µg/m³2026-02-28: 34.0 µg/m³2026-03-01: 32.3 µg/m³2026-03-02: 30.4 µg/m³2026-03-03: 29.2 µg/m³2026-03-04: 34.9 µg/m³2026-03-05: 23.7 µg/m³2026-03-06: 1.0 µg/m³2026-03-07: 1.0 µg/m³2026-03-08: 1.0 µg/m³2026-03-09: 1.0 µg/m³2026-03-10: 1.0 µg/m³2026-03-11: 1.0 µg/m³2026-03-12: 1.0 µg/m³2026-03-13: 1.0 µg/m³2026-03-14: 1.0 µg/m³2026-03-15: 1.0 µg/m³2026-03-16: 1.0 µg/m³2026-03-17: 1.0 µg/m³2026-03-18: 1.0 µg/m³2026-03-19: 1.0 µg/m³2026-03-20: 1.0 µg/m³2026-03-21: 1.0 µg/m³2026-03-22: 1.0 µg/m³2026-03-23: 1.0 µg/m³2026-03-24: 1.0 µg/m³2026-03-25: 13.3 µg/m³2026-03-26: 37.0 µg/m³2026-03-27: 31.5 µg/m³2026-03-28: 39.6 µg/m³2026-03-29: 32.7 µg/m³2026-03-30: 35.8 µg/m³2026-03-31: 29.9 µg/m³2026-04-01: 31.3 µg/m³2026-04-02: 34.0 µg/m³2026-04-03: 37.7 µg/m³2026-04-04: 38.2 µg/m³2026-04-05: 36.3 µg/m³2026-04-06: 28.3 µg/m³2026-04-07: 32.7 µg/m³2026-04-08: 23.5 µg/m³2026-04-09: 27.1 µg/m³2026-04-10: 29.0 µg/m³2026-04-11: 30.9 µg/m³2026-04-12: 29.3 µg/m³2026-04-13: 24.1 µg/m³2026-04-14: 29.9 µg/m³2026-04-15: 33.2 µg/m³2026-04-16: 32.9 µg/m³2026-04-17: 33.5 µg/m³2026-04-18: 35.4 µg/m³2026-04-19: 30.7 µg/m³2026-04-20: 48.2 µg/m³2026-04-21: 31.1 µg/m³2026-04-22: 27.0 µg/m³2026-04-23: 29.6 µg/m³2026-04-24: 19.0 µg/m³2026-04-25: 21.0 µg/m³2026-04-26: 36.6 µg/m³2026-04-27: 40.3 µg/m³2026-04-28: 35.5 µg/m³2026-04-29: 36.5 µg/m³2026-04-30: 36.7 µg/m³2026-05-01: 31.2 µg/m³2026-05-02: 33.8 µg/m³2026-05-03: 20.3 µg/m³2026-05-04: 22.3 µg/m³2026-05-05: 26.4 µg/m³2026-05-06: 30.6 µg/m³2026-05-07: 38.0 µg/m³2026-05-08: 52.8 µg/m³2026-05-09: 31.6 µg/m³2026-05-10: 40.1 µg/m³2026-05-11: 25.5 µg/m³2026-05-12: 24.7 µg/m³2026-05-13: 29.3 µg/m³2026-05-14: 32.1 µg/m³2026-05-15: 32.4 µg/m³2026-05-16: 27.0 µg/m³2026-05-17: 27.6 µg/m³2026-05-18: 30.3 µg/m³2026-05-19: 42.6 µg/m³2026-05-20: 25.5 µg/m³2026-05-21: 31.5 µg/m³2026-05-22: 27.3 µg/m³2026-05-23: 29.3 µg/m³2026-05-24: 26.5 µg/m³2026-05-25: 30.5 µg/m³2026-05-26: 28.0 µg/m³2026-05-27: 23.2 µg/m³2026-05-28: 22.9 µg/m³2026-05-29: 30.5 µg/m³2026-05-30: 32.5 µg/m³2026-05-31: 29.0 µg/m³2026-06-01: 29.9 µg/m³2026-06-02: 30.6 µg/m³2026-06-03: 27.9 µg/m³2026-06-04: 24.5 µg/m³2026-06-05: 20.7 µg/m³2026-06-06: 27.3 µg/m³2026-06-07: 22.0 µg/m³2026-06-08: 22.9 µg/m³2026-06-09: 19.5 µg/m³2026-06-10: 20.3 µg/m³2026-06-11: 5.5 µg/m³2026-06-12: 1.0 µg/m³2026-06-13: 1.0 µg/m³2026-06-14: 1.0 µg/m³2026-06-15: 1.0 µg/m³2026-06-16: 1.0 µg/m³2026-06-17: 1.0 µg/m³2026-06-18: 1.0 µg/m³2026-06-19: 1.0 µg/m³2026-06-20: 1.0 µg/m³2026-06-21: 1.0 µg/m³2026-06-22: 1.0 µg/m³2026-06-23: 1.0 µg/m³2026-06-24: 1.0 µg/m³2026-06-25: 1.0 µg/m³2026-06-26: 1.0 µg/m³2026-06-27: 1.0 µg/m³2026-06-28: 1.0 µg/m³2026-06-29: 11.0 µg/m³2026-06-30: 26.6 µg/m³2026-07-01: 31.2 µg/m³2026-07-02: 28.0 µg/m³2026-07-03: 25.0 µg/m³2026-07-04: 26.9 µg/m³2026-07-05: 27.9 µg/m³2026-07-06: 25.8 µg/m³2026-07-07: 27.3 µg/m³2026-07-08: 23.1 µg/m³2026-07-09: 19.8 µg/m³2026-07-10: 27.7 µg/m³2026-07-11: 24.8 µg/m³2026-07-12: 21.8 µg/m³2026-07-13: 20.5 µg/m³2026-07-14: 28.8 µg/m³2026-07-15: 26.4 µg/m³2026-07-16: 24.8 µg/m³2026-07-17: 23.6 µg/m³2026-07-18: 31.6 µg/m³2026-07-19: 31.7 µg/m³2026-07-20: 35.6 µg/m³2026-07-21: 30.2 µg/m³2026-07-22: 26.3 µg/m³2026-07-23: 24.2 µg/m³2026-07-24: 26.5 µg/m³2026-07-25: 29.4 µg/m³2026-07-26: 24.5 µg/m³2026-07-27: 24.3 µg/m³2026-07-28: 26.3 µg/m³2026-07-29: 29.0 µg/m³2026-07-30: 35.0 µg/m³2026-07-31: 30.3 µg/m³2026-08-01: 29.8 µg/m³2026-08-02: 31.0 µg/m³2026-08-03: 26.3 µg/m³2026-08-04: 33.3 µg/m³2026-08-05: 35.7 µg/m³2026-08-06: 28.2 µg/m³2026-08-07: 26.1 µg/m³2026-08-08: 34.5 µg/m³2026-08-09: 32.8 µg/m³2026-08-10: 29.8 µg/m³2026-08-11: 28.2 µg/m³2026-08-12: 23.8 µg/m³2026-08-13: 30.0 µg/m³2026-08-14: 31.3 µg/m³2026-08-15: 29.1 µg/m³2026-08-16: 31.3 µg/m³2026-08-17: 24.6 µg/m³2026-08-18: 28.0 µg/m³2026-08-19: 26.3 µg/m³2026-08-20: 27.3 µg/m³2026-08-21: 28.2 µg/m³2026-08-22: 27.6 µg/m³2026-08-23: 28.2 µg/m³2026-08-24: 27.4 µg/m³2026-08-25: 24.6 µg/m³2026-08-26: 31.6 µg/m³2026-08-27: 29.2 µg/m³2026-08-28: 28.1 µg/m³2026-08-29: 28.2 µg/m³2026-08-30: 30.5 µg/m³2026-08-31: 37.4 µg/m³2026-09-01: 31.3 µg/m³2026-09-02: 22.9 µg/m³2026-09-03: 29.5 µg/m³2026-09-04: 28.3 µg/m³2026-09-05: 30.8 µg/m³2026-09-06: 29.4 µg/m³2026-09-07: 25.0 µg/m³2026-09-08: 24.6 µg/m³2026-09-09: 23.6 µg/m³2026-09-10: 26.3 µg/m³2026-09-11: 34.0 µg/m³2026-09-12: 34.0 µg/m³2026-09-13: 34.0 µg/m³2026-09-14: 34.0 µg/m³2026-09-15: 34.0 µg/m³2026-09-16: 34.0 µg/m³2026-09-17: 34.0 µg/m³2026-09-18: 34.0 µg/m³2026-09-19: 34.0 µg/m³2026-09-20: 34.1 µg/m³2026-09-21: 34.0 µg/m³2026-09-22: 34.0 µg/m³2026-09-23: 34.0 µg/m³2026-09-24: 34.0 µg/m³2026-09-25: 34.0 µg/m³2026-09-26: 34.0 µg/m³2026-09-27: 34.1 µg/m³2026-09-28: 34.0 µg/m³2026-09-29: 34.2 µg/m³2026-09-30: 34.0 µg/m³
252 of 323 measured days were over the WHO 24-hour guideline (15 µg/m³). One row per month, one square per local day.
Good0–9.0
Moderate9.1–35.4
Sensitive groups35.5–55.4
Unhealthy55.5–125.4
Very unhealthy125.5–225.4
Hazardous225.5+

Last 4 days, hour by hour

15352026-10-01 00:00 UTC: 34.0 µg/m³2026-10-01 01:00 UTC: 34.0 µg/m³2026-10-01 02:00 UTC: 34.0 µg/m³2026-10-01 03:00 UTC: 34.0 µg/m³2026-10-01 04:00 UTC: 34.0 µg/m³2026-10-01 05:00 UTC: 34.0 µg/m³2026-10-01 06:00 UTC: 34.0 µg/m³2026-10-01 07:00 UTC: 34.0 µg/m³2026-10-01 08:00 UTC: 34.0 µg/m³2026-10-01 09:00 UTC: 35.0 µg/m³2026-10-01 10:00 UTC: 35.0 µg/m³2026-10-01 11:00 UTC: 34.0 µg/m³2026-10-01 12:00 UTC: 34.0 µg/m³2026-10-01 13:00 UTC: 34.0 µg/m³2026-10-01 14:00 UTC: 34.0 µg/m³2026-10-01 15:00 UTC: 34.0 µg/m³2026-10-01 16:00 UTC: 35.0 µg/m³2026-10-01 17:00 UTC: 34.0 µg/m³2026-10-01 18:00 UTC: 34.0 µg/m³2026-10-01 19:00 UTC: 34.0 µg/m³2026-10-01 20:00 UTC: 35.0 µg/m³2026-10-01 21:00 UTC: 35.0 µg/m³2026-10-01 22:00 UTC: 35.0 µg/m³2026-10-01 23:00 UTC: 35.0 µg/m³Sep 29Sep 30Oct 1
Times in UTC. Dashed line: WHO 24-hour guideline (15 µg/m³).

Its world rank, day by day

#1#2379OctNovDecJanFebMarAprMayJunJulAugSep
Rank on each day's board (1 = most polluted city that day).

2026 against 2025, month by month

15Jan 2026: 28.5 µg/m³JanFeb 2026: 30.5 µg/m³FebMar 2025: 16.7 µg/m³Mar 2026: 12.6 µg/m³MarApr 2025: 17.8 µg/m³Apr 2026: 32.0 µg/m³AprMay 2025: 19.5 µg/m³May 2026: 30.2 µg/m³MayJun 2025: 9.7 µg/m³Jun 2026: 10.2 µg/m³JunJul 2025: 11.1 µg/m³Jul 2026: 27.0 µg/m³JulAug 2026: 29.3 µg/m³AugSep 2025: 7.4 µg/m³Sep 2026: 31.7 µg/m³SepOct 2025: 10.6 µg/m³OctNovDec 2025: 17.7 µg/m³Dec
Faded bars: 2025. A month shows once it has 10 measured days.

This week against past years

This weekThis week: 34.0 µg/m³34.020252025: 9.2 µg/m³9.22024no data2023no data
Mean PM2.5 for 24 Sept to 30 Sept in each year. Dashed line: WHO 24-hour guideline.

Monitors

StationOperatorType
Industriales Potosinos AsociadosMexico SINAICA Terms and ConditionsSinaica MexicoReference

The city's value is the median of its reference monitors each hour, when at least a third of them report (three are always enough); low-cost sensors are listed but not counted when reference monitors exist. Data via OpenAQ; licences as listed. How we rank. Embed this on your site.

Use this page

SmogRank, PM2.5 daily means, San Luis Potosí, Mexico, 1 Oct 2025 – 30 Sep 2026, smogrank.com/mx/san-luis-potosi (accessed 2 Oct 2026).

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Other cities in Mexico

30-day averages, µg/m³. All of Mexico.

Updated 2026-10-02 00:07 UTC. Values are PM2.5 in µg/m³ (fine particles), the median of each city's monitors.