SmogRank / Canada / Alberta / Calgary

Calgary, month by month

Calgary has a measured daily mean on 1,305 days since 1 January 2023. Its worst month was May 2023, at 80 US AQI (24.6 µg/m³), 79th of 1,600 cities on that month's world ranking. Its cleanest was April 2023, at 28 US AQI (5.1 µg/m³). 2025 averaged 53 US AQI (10.2 µg/m³), against 53 US AQI (10.3 µg/m³) in 2024.

Every month since 2023

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

Calgary's worst months

MonthUS AQIDays measuredWorld rankEpisode
May 2023 8024.6 µg/m³31 of 3179thof 1,600North-western United States and Canada, May 2023
North-western Canada and United States, May 2023and 1 more
September 2025 7924.0 µg/m³30 of 30152ndof 3,104North-western Canada and United States, September 2025
North-western United States and Canada, August and September 2025
July 2024 7421.2 µg/m³30 of 3195thof 2,566North-western United States and Canada, July 2024
August 2023 7019.4 µg/m³29 of 31134thof 1,980Northern United States and Canada, August and September 2023
North-western United States and Canada, August 2023
September 2023 7019.4 µg/m³30 of 30106thof 2,176Northern United States and Canada, August and September 2023
July 2026 7019.3 µg/m³31 of 31362ndof 2,784North-western United States and Canada, July and August 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.

Calgary's worst days

DayUS AQIEpisode
4 Sept 2023 218143.0 µg/m³Northern United States and Canada, August and September 2023
24 Jul 2024 215139.5 µg/m³North-western United States and Canada, July 2024
17 May 2023 206130.5 µg/m³Northern United States and Canada, May 2023
16 May 2023 191112.5 µg/m³Northern United States and Canada, May 2023
11 Jun 2025 190110.5 µg/m³North-western Canada and United States, June 2025
2 Sept 2025 182100.3 µg/m³North-western United States and Canada, August and September 2025
20 May 2023 18198.0 µg/m³North-western United States and Canada, May 2023
24 Jul 2026 17691.3 µg/m³North-western United States and Canada, July and August 2026
5 Sept 2023 17082.9 µg/m³Northern United States and Canada, August and September 2023
23 Jul 2026 16474.7 µg/m³North-western United States and Canada, July and August 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, Calgary, 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/calgary/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.

Calgary 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).