SmogRank / Canada / Nova Scotia / Sydney

Sydney, month by month

Sydney, Nova Scotia has a measured daily mean on 1,030 days since 1 January 2023. Its worst month was July 2025, at 36 US AQI (6.5 µg/m³), 2,135th of 2,889 cities on that month's world ranking. Its cleanest was September 2026, at 16 US AQI (2.8 µg/m³).

Every month since 2023

202622 so far277 days measured2,750th of 2,791 in the world
Jan21#2,529Feb25#2,658Mar22#2,823Apr23#2,696May19#2,743Jun20#2,363Jul30#2,540Aug23#2,825Sep16#2,936Oct17#2,663
202522 for the year338 days measured2,635th of 2,681 in the world
Jan16 daysFeb19#2,574Mar21#2,708Apr19#2,874May21#2,661Jun24#2,371Jul36#2,135Aug26#2,747Sep16#3,065Oct20#2,494Nov18#2,638Dec21#2,886
2024too few days for a mean (a year needs 257)229 days measured
Jan24#2,199Feb16 daysMar21 daysApr22#2,229May18#2,555Jun16 daysJul26#2,346Aug29#1,850Sep22#1,926Oct14 daysNovnoneDecnone
2023too few days for a mean (a year needs 256)186 days measured
Jan24#1,139Feb3 daysMar11 daysApr10 daysMaynoneJun20 daysJul12 daysAug15 daysSep20 daysOct21 daysNov20 daysDec29#1,973
Each square is a month's mean PM2.5 in US AQI from Sydney'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 Sydney 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

17 months
MonthWhy
Jan 202516 of 31 days measured; a month needs 22. The others: 15 with under 18 hours of readings or readings that failed our checks.
Dec 2024No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Nov 2024No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Oct 202414 of 31 days measured; a month needs 22. The others: 17 with under 18 hours of readings or readings that failed our checks.
Jun 202416 of 30 days measured; a month needs 21. The others: 14 with under 18 hours of readings or readings that failed our checks.
Mar 202421 of 31 days measured; a month needs 22. The others: 1 missing from OpenAQ's archive, 9 with under 18 hours of readings or readings that failed our checks.
Feb 202416 of 29 days measured; a month needs 21. The others: 1 missing from OpenAQ's archive, 12 with under 18 hours of readings or readings that failed our checks.
Nov 202320 of 30 days measured; a month needs 21. The others: 10 with under 18 hours of readings or readings that failed our checks.
Oct 202321 of 31 days measured; a month needs 22. The others: 10 with under 18 hours of readings or readings that failed our checks.
Sep 202320 of 30 days measured; a month needs 21. The others: 10 with under 18 hours of readings or readings that failed our checks.
Aug 202315 of 31 days measured; a month needs 22. The others: 16 with under 18 hours of readings or readings that failed our checks.
Jul 202312 of 31 days measured; a month needs 22. The others: 1 missing from OpenAQ's archive, 18 with under 18 hours of readings or readings that failed our checks.
Jun 202320 of 30 days measured; a month needs 21. The others: 10 with under 18 hours of readings or readings that failed our checks.
May 2023No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Apr 202310 of 30 days measured; a month needs 21. The others: 3 missing from OpenAQ's archive, 17 with under 18 hours of readings or readings that failed our checks.
Mar 202311 of 31 days measured; a month needs 22. The others: 20 missing from OpenAQ's archive.
Feb 20233 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.

Sydney's worst months

MonthUS AQIDays measuredWorld rank
July 2025 366.5 µg/m³31 of 312,135thof 2,889
July 2026 305.4 µg/m³31 of 312,540thof 2,784
December 2023 295.3 µg/m³29 of 311,973rdof 2,247
August 2024 295.3 µg/m³31 of 311,850thof 2,010
August 2025 264.7 µg/m³31 of 312,747thof 2,901
July 2024 264.6 µg/m³25 of 312,346thof 2,566

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.

Sydney's worst days

DayUS AQI
16 Jul 2025 8225.5 µg/m³
4 Jul 2026 6416.3 µg/m³
27 Sept 2023 6315.8 µg/m³
4 Aug 2025 6114.3 µg/m³
6 Sept 2023 5913.5 µg/m³
18 Dec 2023 5712.1 µg/m³
29 Sept 2023 5612.0 µg/m³
14 Aug 2025 5611.9 µg/m³
28 Jul 2025 5611.7 µg/m³
15 Jul 2026 5611.7 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, Sydney, Nova Scotia, Canada, 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/ca/sydney/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.

Sydney 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).