SmogRank / Peru / Lima region / San Francisco De Borja
San Francisco De Borja, month by month
San Francisco De Borja has a measured daily mean on 1,034 days since 1 January 2023. Its worst month was June 2024, at 108 US AQI (38.5 µg/m³), 35th of 2,563 cities on that month's world ranking. Its cleanest was January 2024, at 58 US AQI (12.8 µg/m³). 2025 averaged 78 US AQI (23.6 µg/m³), against 77 US AQI (23.3 µg/m³) in 2024.
Every month since 2023
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
15 months
| Month | Why |
|---|---|
| Oct 2026 | 5 of 11 days measured; a month needs 8. The others: 6 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 readings for part of the day (a day needs 18 hours). |
| 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. |
| 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. |
| Dec 2023 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Nov 2023 | 5 of 30 days measured; a month needs 21. The others: 25 with under 18 hours of readings or readings that failed our checks. |
| Oct 2023 | 16 of 31 days measured; a month needs 22. The others: 15 with under 18 hours of readings or readings that failed our checks. |
| Aug 2023 | 18 of 31 days measured; a month needs 22. The others: 13 with under 18 hours of readings or readings that failed our checks. |
| Jul 2023 | 18 of 31 days measured; a month needs 22. The others: 1 missing from OpenAQ's archive, 12 with under 18 hours of readings or readings that failed our checks. |
| Jun 2023 | No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks. |
| May 2023 | No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks. |
| Apr 2023 | 14 of 30 days measured; a month needs 21. The others: 3 missing from OpenAQ's archive, 13 with under 18 hours of readings or readings that failed our checks. |
| Mar 2023 | 8 of 31 days measured; a month needs 22. The others: 20 missing from OpenAQ's archive, 3 with under 18 hours of readings or readings that failed our checks. |
| Feb 2023 | 3 of 28 days measured; a month needs 20. The others: 25 missing from OpenAQ's archive. |
A day counts once 18 hours of it are measured; a month needs 70% of its days.
San Francisco De Borja's worst months
| Month | US AQI | World rank |
|---|---|---|
| June 2024 | 10838.5 µg/m³ | 35thof 2,563 |
| May 2025 | 9532.6 µg/m³ | 123rdof 2,826 |
| July 2024 | 9231.1 µg/m³ | 57thof 2,566 |
| September 2025 | 9130.6 µg/m³ | 77thof 3,104 |
| May 2026 | 8929.6 µg/m³ | 178thof 2,874 |
| May 2024 | 8929.4 µg/m³ | 71stof 2,684 |
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.
San Francisco De Borja's worst days
| Day | US AQI |
|---|---|
| 1 May 2026 | 16980.8 µg/m³ |
| 2 May 2026 | 16474.2 µg/m³ |
| 3 May 2026 | 16473.4 µg/m³ |
| 27 Jun 2024 | 16373.3 µg/m³ |
| 20 Jun 2024 | 15561.9 µg/m³ |
| 21 Jun 2024 | 15459.8 µg/m³ |
| 15 Sept 2025 | 15357.9 µg/m³ |
| 26 Jun 2024 | 15155.9 µg/m³ |
| 28 May 2025 | 15155.5 µg/m³ |
| 2 Jun 2025 | 14453.1 µg/m³ |
Daily means, the highest since 1 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, San Francisco De Borja, Peru, 1 Jan 2023 – 10 Oct 2026. Monitor data from Senamhi via OpenAQ; sources listed at smogrank.com/sources. smogrank.com/pe/san-francisco-de-borja/history (accessed 12 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.
San Francisco De Borja now: the last 24 hours, its ranks today and the last 12 months day by day.
Updated 2026-10-12 20:07 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).