SmogRank / Mexico / Sonora / Nogales
Nogales, month by month
Nogales has a measured daily mean on 1,314 days since 1 January 2023. Its worst month was December 2024, at 85 US AQI (27.4 µg/m³), 122nd of 2,616 cities on that month's world ranking. Its cleanest was July 2026, at 41 US AQI (7.3 µg/m³). 2025 averaged 59 US AQI (13.2 µg/m³), against 58 US AQI (12.9 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
2 months
| Month | Why |
|---|---|
| Mar 2025 | 4 of 31 days measured; a month needs 22. The others: 27 with under 18 hours of readings or readings that failed our checks. |
| Feb 2025 | 6 of 28 days measured; a month needs 20. The others: 22 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.
Nogales's worst months
| Month | US AQI | World rank | Episode |
|---|---|---|---|
| December 2024 | 8527.4 µg/m³ | 122ndof 2,616 | South-western United States and Mexico, December 2024 to January 2025 |
| November 2025 | 7220.5 µg/m³ | 396thof 2,715 | – |
| December 2025 | 7220.4 µg/m³ | 491stof 3,006 | – |
| December 2023 | 6918.8 µg/m³ | 182ndof 2,247 | – |
| January 2025 | 6717.7 µg/m³ | 376thof 2,474 | Western United States and Mexico, January and February 2025 South-western United States and Mexico, December 2024 to January 2025 |
| October 2025 | 6617.2 µg/m³ | 317thof 2,614 | – |
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.
Nogales's worst days
| Day | US AQI | Episode |
|---|---|---|
| 21 Dec 2024 | 193115.0 µg/m³ | – |
| 1 Jan 2024 | 17690.7 µg/m³ | – |
| 20 Dec 2024 | 15358.1 µg/m³ | – |
| 31 Dec 2023 | 13850.6 µg/m³ | – |
| 1 Jan 2025 | 12645.6 µg/m³ | South-western United States and Mexico, December 2024 to January 2025 |
| 7 Oct 2025 | 12043.2 µg/m³ | – |
| 14 Dec 2024 | 11842.3 µg/m³ | – |
| 19 Dec 2024 | 11039.3 µg/m³ | – |
| 19 Jan 2025 | 10838.4 µg/m³ | – |
| 8 Jan 2025 | 10738.0 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, Nogales, Mexico, 1 Jan 2023 – 11 Oct 2026. Monitor data from AirNow, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/mx/nogales/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.
Nogales 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).