SmogRank / Canada / British Columbia / Nanaimo

Nanaimo, month by month

Nanaimo has a measured daily mean on 1,251 days since 1 January 2023. Its worst month was August 2023, at 42 US AQI (7.5 µg/m³), 1,146th of 1,980 cities on that month's world ranking. Its cleanest was April 2024, at 12 US AQI (2.2 µg/m³). 2025 averaged 25 US AQI (4.5 µg/m³), against 19 US AQI (3.4 µg/m³) in 2024.

Every month since 2023

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

3 months
MonthWhy
Jan 202621 of 31 days measured; a month needs 22. The others: 10 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 20231 of 28 days measured; a month needs 20. The others: 25 missing from OpenAQ's archive, 2 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.

Nanaimo's worst months

MonthUS AQIDays measuredWorld rankEpisode
August 2023 427.5 µg/m³30 of 311,146thof 1,980North-western United States and Canada, August 2023
August 2025 417.4 µg/m³31 of 312,018thof 2,901–
September 2025 397.0 µg/m³30 of 301,690thof 3,104–
July 2026 346.2 µg/m³27 of 312,374thof 2,784–
May 2023 325.7 µg/m³26 of 311,342ndof 1,600–
August 2024 295.2 µg/m³30 of 311,862ndof 2,010–

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.

Nanaimo's worst days

DayUS AQIEpisode
27 Aug 2023 9030.2 µg/m³North-western United States and Canada, August 2023
30 May 2023 7823.6 µg/m³–
26 Aug 2023 7622.7 µg/m³North-western United States and Canada, August 2023
28 Aug 2023 7421.5 µg/m³North-western United States and Canada, August 2023
25 Aug 2023 7119.8 µg/m³North-western United States and Canada, August 2023
5 Sept 2025 7019.1 µg/m³–
6 Sept 2025 6918.8 µg/m³–
14 Aug 2025 6918.7 µg/m³–
22 Jul 2026 6918.5 µg/m³–
21 Jul 2026 6717.5 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, Nanaimo, 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/nanaimo/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.

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

Updated 2026-10-12 19:07 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).