SmogRank / Canada / Ontario / North Bay

North Bay, month by month

North Bay has a measured daily mean on 1,274 days since 1 January 2023. Its worst month was June 2023, at 121 US AQI (43.6 µg/m³), 32nd of 1,603 cities on that month's world ranking. Its cleanest was April 2023, at 14 US AQI (2.5 µg/m³). 2025 averaged 33 US AQI (5.9 µg/m³), against 26 US AQI (4.6 µg/m³) in 2024.

Every month since 2023

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

2 months
MonthWhy
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.

North Bay's worst months

MonthUS AQIDays measuredWorld rankEpisode
June 2023 12143.6 µg/m³30 of 3032ndof 1,603Eastern United States and Canada, June and July 2023
United States and Canada, June 2023and 1 more
July 2025 6114.6 µg/m³31 of 31440thof 2,889North-eastern United States and Canada, 29 July to 9 August 2025
North-eastern United States and Canada, 24 to 28 July 2025and 1 more
July 2026 5913.3 µg/m³31 of 31682ndof 2,784Northern United States and Canada, July 2026
August 2023 5813.1 µg/m³31 of 31267thof 1,980Ontario, Canada, August 2023
July 2023 5410.5 µg/m³29 of 31600thof 1,432Eastern United States and Canada, June and July 2023
June 2025 5310.3 µg/m³30 of 301,216thof 2,508Northern United States and Canada, May and June 2025

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.

North Bay's worst days

DayUS AQIEpisode
25 Jun 2023 500+397.0 µg/m³Eastern United States and Canada, June and July 2023
26 Jun 2023 214139.0 µg/m³Eastern United States and Canada, June and July 2023
15 Aug 2023 16676.7 µg/m³–
16 Jul 2026 15663.0 µg/m³Northern United States and Canada, July 2026
14 Jul 2025 15662.0 µg/m³Northern United States and Canada, July 2025
18 Jun 2023 15460.4 µg/m³United States and Canada, June 2023
30 Jul 2025 14453.0 µg/m³North-eastern United States and Canada, 29 July to 9 August 2025
28 Jun 2023 14352.5 µg/m³Eastern United States and Canada, June and July 2023
3 Aug 2025 14051.5 µg/m³North-eastern United States and Canada, 29 July to 9 August 2025
18 Jul 2026 13147.6 µg/m³Northern United States and Canada, July 2026

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, North Bay, 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/north-bay/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.

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

Updated 2026-10-12 22:07 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).