SmogRank / Australia / Queensland / Emerald

Emerald, month by month

Emerald has a measured daily mean on 1,113 days since 1 January 2023. Its worst month was October 2025, at 64 US AQI (16.1 µg/m³), 332nd of 2,614 cities on that month's world ranking. Its cleanest was June 2026, at 19 US AQI (3.4 µg/m³). 2025 averaged 33 US AQI (5.9 µg/m³), against 34 US AQI (6.1 µg/m³) in 2024.

Every month since 2023

2026too few days for a mean (a year needs 200)183 days measured

Jan18 daysFeb23#2,713 Mar21#2,834 Apr27#2,525 May29#2,220 Jun19#2,385Jul10 daysAugnoneSepnoneOct30#2,091

202533 for the year361 days measured2,380th of 2,681 in the world

Jan24#2,323 Feb24#2,488 Mar22#2,677 Apr21#2,814 May24#2,515 Jun21#2,423 Jul22#2,771 Aug24#2,784 Sep44#1,295 Oct64#332 Nov46#1,482 Dec34#2,408

202434 for the year336 days measured1,752nd of 2,097 in the world

Jan31#1,957Feb17 daysMar20 daysApr22#2,259 May23#2,425 Jun29#2,216 Jul27#2,306 Aug38#1,563 Sep53#423 Oct42#916 Nov43#1,444 Dec31#2,174

2023too few days for a mean (a year needs 256)233 days measured

Jan32#1,022Feb2 daysMar9 daysApr19 daysMay17 daysJun11 daysJul18 daysAug44#1,010 Sep55#401Oct20 daysNov43#1,200 Dec50#952

Each square is a month's mean PM2.5 in US AQI from Emerald'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 Emerald 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

13 months

Month	Why
Sep 2026	No day measured. The others: 30 with readings for part of the day (a day needs 18 hours).
Aug 2026	No day measured. The others: 31 with readings for part of the day (a day needs 18 hours).
Jul 2026	10 of 31 days measured; a month needs 22. The others: 18 with readings for part of the day (a day needs 18 hours), 3 with under 18 hours of readings or readings that failed our checks.
Jan 2026	18 of 31 days measured; a month needs 22. The others: 13 with readings left out by our checks.
Mar 2024	20 of 31 days measured; a month needs 22. The others: 10 with readings for part of the day (a day needs 18 hours), 1 with readings left out by our checks.
Feb 2024	17 of 29 days measured; a month needs 21. The others: 1 with no readings from the monitor, 10 with readings left out by our checks, 1 missing from OpenAQ's archive.
Oct 2023	20 of 31 days measured; a month needs 22. The others: 11 with readings for part of the day (a day needs 18 hours).
Jul 2023	18 of 31 days measured; a month needs 22. The others: 1 with no readings from the monitor, 11 with readings for part of the day (a day needs 18 hours), 1 missing from OpenAQ's archive.
Jun 2023	11 of 30 days measured; a month needs 21. The others: 19 with readings for part of the day (a day needs 18 hours).
May 2023	17 of 31 days measured; a month needs 22. The others: 14 with readings for part of the day (a day needs 18 hours).
Apr 2023	19 of 30 days measured; a month needs 21. The others: 1 with no readings from the monitor, 8 with readings for part of the day (a day needs 18 hours), 2 missing from OpenAQ's archive.
Mar 2023	9 of 31 days measured; a month needs 22. The others: 3 with readings for part of the day (a day needs 18 hours), 19 missing from OpenAQ's archive.
Feb 2023	2 of 28 days measured; a month needs 20. The others: 1 with readings for part of the day (a day needs 18 hours), 25 missing from OpenAQ's archive.

A day counts once 18 hours of it are measured; a month needs 70% of its days.

Emerald's worst months

Month	US AQI	Days measured	World rank
October 2025	6416.1 µg/m³	31 of 31	332ndof 2,614
September 2023	5511.2 µg/m³	30 of 30	401stof 2,176
September 2024	5310.2 µg/m³	30 of 30	423rdof 2,010
December 2023	509.0 µg/m³	30 of 31	952ndof 2,247
November 2025	468.2 µg/m³	30 of 30	1,482ndof 2,715
August 2023	448.0 µg/m³	25 of 31	1,010thof 1,980

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.

Emerald's worst days

Day	US AQI
1 Oct 2025	15256.4 µg/m³
28 Oct 2023	13247.9 µg/m³
22 Sept 2024	12746.2 µg/m³
20 Oct 2025	10436.9 µg/m³
30 Sept 2025	8929.3 µg/m³
23 Sept 2023	8828.7 µg/m³
2 Oct 2025	8728.6 µg/m³
29 Oct 2023	8225.9 µg/m³
27 Sept 2025	8225.6 µg/m³
27 Oct 2023	8125.0 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, Emerald, Australia, 1 Jan 2023 – 12 Oct 2026. Monitor data from Queensland Government, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/au/emerald/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.

Emerald now: the last 24 hours, its ranks today and the last 12 months day by day.

Updated 2026-10-12 18:07 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).