SmogRank / Canada / Ontario / Brooklin

Brooklin, month by month

Brooklin has a measured daily mean on 522 days since 17 July 2023. Its worst month was August 2024, at 46 US AQI (8.3 µg/m³), 1,135th of 2,010 cities on that month's world ranking. Its cleanest was November 2024, at 21 US AQI (3.7 µg/m³).

Every month since 2023

2026too few days for a mean (a year needs 199)0 days measured
JannoneFebnoneMarnoneAprnoneMaynoneJunnoneJulnoneAugnoneSepnoneOctnone
2025too few days for a mean (a year needs 256)19 days measured
Jan14 daysFeb5 daysMarnoneAprnoneMaynoneJunnoneJulnoneAugnoneSepnoneOctnoneNovnoneDecnone
202434 for the year339 days measured1,722nd of 2,097 in the world
Jan37#1,623Feb31#1,989Mar31#1,248Apr28#1,973May32#2,073Jun43#1,392Jul41#1,613Aug46#1,135Sep32#1,594Oct32#1,557Nov21#2,491Dec40#1,641
2023too few days for a mean (a year needs 256)164 days measured
JanFebMarAprMayJunJul15 daysAug41#1,177Sep38#1,546Oct32#1,587Nov33#1,749Dec40#1,497
Each square is a month's mean PM2.5 in US AQI from Brooklin'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 Brooklin marked; each year, the year's.
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

23 months
MonthWhy
Oct 2026No day measured.
Sep 2026No day measured.
Aug 2026No day measured.
Jul 2026No day measured.
Jun 2026No day measured.
May 2026No day measured.
Apr 2026No day measured.
Mar 2026No day measured.
Feb 2026No day measured.
Jan 2026No day measured.
Dec 2025No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Nov 2025No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Oct 2025No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Sep 2025No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Aug 2025No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Jul 2025No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Jun 2025No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
May 2025No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Apr 2025No day measured. The others: 30 with under 18 hours of readings or readings that failed our checks.
Mar 2025No day measured. The others: 31 with under 18 hours of readings or readings that failed our checks.
Feb 20255 of 28 days measured; a month needs 20. The others: 23 with under 18 hours of readings or readings that failed our checks.
Jan 202514 of 31 days measured; a month needs 22. The others: 17 with under 18 hours of readings or readings that failed our checks.
Jul 202315 of 31 days measured; a month needs 22.

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

Brooklin's worst months

MonthUS AQIDays measuredWorld rankEpisode
August 2024 468.3 µg/m³27 of 311,135thof 2,010–
June 2024 437.8 µg/m³29 of 301,392ndof 2,563–
August 2023 417.4 µg/m³29 of 311,177thof 1,980–
July 2024 417.3 µg/m³23 of 311,613thof 2,566–
December 2023 407.2 µg/m³30 of 311,497thof 2,247–
December 2024 407.2 µg/m³30 of 311,641stof 2,616South-eastern Canada and United States, December 2024

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.

Brooklin's worst days

DayUS AQIEpisode
18 Jun 2024 9030.2 µg/m³–
10 Dec 2024 9030.1 µg/m³–
28 Dec 2024 8125.2 µg/m³South-eastern Canada and United States, December 2024
26 Jul 2023 8125.0 µg/m³Northern United States and Canada, July 2023
17 Jul 2023 7119.8 µg/m³–
3 Aug 2023 7019.3 µg/m³–
23 Feb 2025 7019.2 µg/m³–
16 Nov 2023 6818.3 µg/m³–
7 Dec 2023 6717.9 µg/m³–
28 Jul 2023 6717.6 µg/m³–

Daily means, the highest since 17 Jul 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, Brooklin, Canada, 17 Jul 2023 – 11 Oct 2026. Monitor data from AirNow, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/ca/brooklin/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.

Brooklin 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).