SmogRank / Canada / Ontario / Newmarket

Newmarket, month by month

Newmarket has a measured daily mean on 1,142 days since 17 July 2023. Its worst month was July 2026, at 74 US AQI (21.2 µg/m³), 288th of 2,784 cities on that month's world ranking. Its cleanest was April 2024, at 20 US AQI (3.6 µg/m³). 2025 averaged 44 US AQI (8.0 µg/m³), against 35 US AQI (6.3 µg/m³) in 2024.

Every month since 2023

2023too few days for a mean (a year needs 256)160 days measured
Each square is a month's mean PM2.5 in US AQI from Newmarket'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 Newmarket 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

1 month
MonthWhy
Jul 202311 of 31 days measured; a month needs 22. The others: 4 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.

Newmarket's worst months

MonthUS AQIDays measuredWorld rankEpisode
July 2026 7421.2 µg/m³31 of 31288thof 2,784Northern United States and Canada, July 2026
July 2025 6315.3 µg/m³31 of 31383rdof 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
August 2025 6215.2 µg/m³31 of 31342ndof 2,901South-eastern Canada and United States, August 2025
North-eastern United States and Canada, 29 July to 9 August 2025
June 2025 6114.4 µg/m³30 of 30504thof 2,508Northern United States and Canada, May and June 2025
August 2023 5511.4 µg/m³31 of 31407thof 1,980Ontario, Canada, August 2023
February 2026 5310.0 µg/m³27 of 281,391stof 2,866North-eastern United States and Canada, 14 to 19 February 2026

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.

Newmarket's worst days

DayUS AQIEpisode
16 Jul 2026 222147.0 µg/m³Northern United States and Canada, July 2026
15 Jul 2026 17488.6 µg/m³Northern United States and Canada, July 2026
17 Jul 2026 16575.3 µg/m³Northern United States and Canada, July 2026
14 Jul 2025 15764.0 µg/m³Northern United States and Canada, July 2025
3 Aug 2025 15460.2 µg/m³North-eastern United States and Canada, 29 July to 9 August 2025
6 Jun 2025 14653.7 µg/m³Northern United States and Canada, May and June 2025
18 Jul 2026 14352.6 µg/m³Northern United States and Canada, July 2026
4 Aug 2025 13348.5 µg/m³North-eastern United States and Canada, 29 July to 9 August 2025
31 Jul 2025 12946.8 µg/m³North-eastern United States and Canada, 29 July to 9 August 2025
5 Aug 2025 10938.6 µg/m³North-eastern United States and Canada, 29 July to 9 August 2025

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, Newmarket, 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/newmarket/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.

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

Updated 2026-10-12 21:07 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).