SmogRank / Peru / Lima region / Santa María
Santa María, month by month
Santa María, Lima region has a measured daily mean on 840 days since 26 January 2024. Its worst month was May 2024, at 188 US AQI (108.9 µg/m³), 3rd of 2,684 cities on that month's world ranking. Its cleanest was March 2025, at 67 US AQI (17.9 µg/m³). 2025 averaged 117 US AQI (41.9 µg/m³), against 161 US AQI (70.2 µg/m³) in 2024.
Every month since 2024
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
8 months
| Month | Why |
|---|---|
| Oct 2026 | 4 of 11 days measured; a month needs 8. The others: 2 with no readings from the monitor, 5 with readings for part of the day (a day needs 18 hours). |
| Sep 2026 | 7 of 30 days measured; a month needs 21. The others: 23 with under 18 hours of readings or readings that failed our checks. |
| Aug 2026 | 11 of 31 days measured; a month needs 22. The others: 20 with under 18 hours of readings or readings that failed our checks. |
| Jul 2026 | 10 of 31 days measured; a month needs 22. The others: 21 with under 18 hours of readings or readings that failed our checks. |
| May 2025 | 14 of 31 days measured; a month needs 22. The others: 17 with under 18 hours of readings or readings that failed our checks. |
| Feb 2025 | 18 of 28 days measured; a month needs 20. The others: 10 with under 18 hours of readings or readings that failed our checks. |
| Mar 2024 | 20 of 31 days measured; a month needs 22. The others: 11 with under 18 hours of readings or readings that failed our checks. |
| Jan 2024 | 5 of 31 days measured; a month needs 22. The others: 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.
Santa María's worst months
| Month | US AQI | World rank |
|---|---|---|
| May 2024 | 188108.9 µg/m³ | 3rdof 2,684 |
| June 2024 | 188107.8 µg/m³ | 1stof 2,563 |
| August 2024 | 17589.2 µg/m³ | 1stof 2,010 |
| July 2024 | 16879.6 µg/m³ | 7thof 2,566 |
| September 2024 | 16574.8 µg/m³ | 2ndof 2,010 |
| October 2024 | 16068.2 µg/m³ | 8thof 2,020 |
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.
Santa María's worst days
| Day | US AQI |
|---|---|
| 26 Jun 2024 | 250175.0 µg/m³ |
| 27 May 2024 | 224149.0 µg/m³ |
| 6 Jun 2024 | 224149.0 µg/m³ |
| 25 Aug 2024 | 221146.0 µg/m³ |
| 26 May 2024 | 218142.5 µg/m³ |
| 29 May 2024 | 217142.0 µg/m³ |
| 25 May 2024 | 217141.5 µg/m³ |
| 24 May 2024 | 212137.0 µg/m³ |
| 27 Jun 2024 | 212137.0 µg/m³ |
| 29 Jun 2024 | 212137.0 µg/m³ |
Daily means, the highest since 26 Jan 2024; 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, Santa María, Lima region, Peru, 26 Jan 2024 – 10 Oct 2026. Monitor data from Senamhi via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/pe/santa-maria/history (accessed 13 Oct 2026).
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.
Santa María now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-13 02:07 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).