SmogRank / Canada / British Columbia / Chilliwack

Chilliwack, month by month

Chilliwack has a measured daily mean on 1,292 days since 1 January 2023. Its worst month was August 2026, at 65 US AQI (16.8 µg/m³), 329th of 3,210 cities on that month's world ranking. Its cleanest was March 2025, at 17 US AQI (3.1 µg/m³). 2025 averaged 29 US AQI (5.3 µg/m³), against 26 US AQI (4.7 µg/m³) in 2024.

Every month since 2023

Each square is a month's mean PM2.5 in US AQI from Chilliwack'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 Chilliwack marked; each year, the year's. A dashed square is the running month, so far.
Good0–50
Moderate51–100
Unhealthy for 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 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.

Chilliwack's worst months

MonthUS AQIDays measuredWorld rankEpisode
August 2026 6516.8 µg/m³31 of 31329thof 3,210North-western United States and Canada, 25 to 26 August 2026
North-western United States and Canada, 4 to 22 August 2026and 1 more
August 2023 6416.2 µg/m³29 of 31172ndof 1,980Northern United States and Canada, August and September 2023
North-western United States and Canada, August 2023
September 2025 5310.2 µg/m³30 of 30651stof 3,245North-western United States and Canada, August and September 2025
August 2025 468.2 µg/m³31 of 311,814thof 3,095North-western United States and Canada, August and September 2025
July 2026 458.1 µg/m³31 of 311,981stof 3,035North-western United States and Canada, July and August 2026
September 2026 427.5 µg/m³30 of 301,197thof 3,347–

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.

Chilliwack's worst days

DayUS AQIEpisode
20 Aug 2023 193115.0 µg/m³North-western United States and Canada, August 2023
5 Aug 2026 16981.5 µg/m³North-western United States and Canada, 4 to 22 August 2026
4 Aug 2026 14252.1 µg/m³North-western United States and Canada, 4 to 22 August 2026
North-western United States and Canada, July and August 2026
6 Aug 2026 14051.5 µg/m³North-western United States and Canada, 4 to 22 August 2026
25 Aug 2023 13649.7 µg/m³North-western United States and Canada, August 2023
27 Aug 2023 13248.0 µg/m³North-western United States and Canada, August 2023
25 Aug 2026 12746.0 µg/m³North-western United States and Canada, 25 to 26 August 2026
21 Aug 2026 12244.0 µg/m³North-western United States and Canada, 4 to 22 August 2026
22 Jul 2026 11742.2 µg/m³North-western United States and Canada, July and August 2026
26 Aug 2023 10838.3 µg/m³North-western United States and Canada, August 2023

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, Chilliwack, Canada, 1 Jan 2023 – 12 Oct 2026. Monitor data from AirNow, via OpenAQ and from the publisher directly; sources listed at smogrank.com/sources. smogrank.com/ca/chilliwack/history (accessed 13 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.

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

Updated 2026-10-13 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).