SmogRank / Castlegar / Medicine Hat

Castlegar vs Medicine Hat: PM2.5 compared

Over the last year, Castlegar's air was about 1.6× as polluted as Medicine Hat's: PM2.5 averaged 11.0 µg/m³ against 6.8, on the 321 days both cities were measured. Castlegar had the dirtier air on 234 of those days, Medicine Hat on 80. Castlegar was over the WHO's daily guideline of 15 µg/m³ on 39 of them, Medicine Hat on 18.

Right now

Castlegar#770on the 24-hour board of 2,002, at 45 US AQI (8.1 µg/m³)
Medicine Hat#871on the 24-hour board of 2,002, at 41 US AQI (7.4 µg/m³)

The last year, day by day

Castlegar
Medicine Hat
Each city's daily mean from 7 Oct 2025 to 6 Oct 2026, one stripe a day, coloured by band. A blank stripe is a day without a daily mean.

Month by month

Castlegar, Nov 2025: 9.0 µg/m³Medicine Hat, Nov 2025: 5.7 µg/m³Nov2025Castlegar, Dec 2025: 6.3 µg/m³Medicine Hat, Dec 2025: 5.8 µg/m³DecCastlegar, Jan 2026: 8.4 µg/m³Medicine Hat, Jan 2026: 6.8 µg/m³Jan2026Castlegar, Feb 2026: 6.1 µg/m³Medicine Hat, Feb 2026: 4.9 µg/m³FebCastlegar, Mar 2026: 6.2 µg/m³Medicine Hat, Mar 2026: 5.7 µg/m³MarCastlegar, Apr 2026: 6.6 µg/m³Medicine Hat, Apr 2026: 4.6 µg/m³AprCastlegar, May 2026: 5.9 µg/m³Medicine Hat, May 2026: 4.7 µg/m³MayCastlegar, Jun 2026: 4.5 µg/m³Medicine Hat, Jun 2026: 3.7 µg/m³JunCastlegar, Jul 2026: 19.7 µg/m³Medicine Hat, Jul 2026: 14.6 µg/m³JulCastlegar, Aug 2026: 39.3 µg/m³Medicine Hat, Aug 2026: 13.3 µg/m³AugCastlegar, Sep 2026: 8.0 µg/m³Medicine Hat, Sep 2026: 4.8 µg/m³SepOct
Monthly means in µg/m³ over the days both cities were measured. Solid: Castlegar. Faded: Medicine Hat. A month shows once both share 10 such days. Dashed line: the WHO daily guideline, 15 µg/m³.

Year by year

YearCastlegarMedicine HatDays both measuredDays Castlegar was worse
2026 so far5740245181
20254243343188
20244039347189
20235347276179

Means in US AQI over the days both cities were measured that year; a year shows once they share 30 such days.

Each city's worst days

Castlegar

Medicine Hat

Daily means in US AQI, with µg/m³ beside them, since the index stops at its top value, over the days both cities were measured in the last year. Each date opens that day's world board.

Compare either city with another

Castlegar

Side by side with Creston (the nearest), Edmonton (Canada's 2nd worst on 30 days), Gujranwala (the world's worst on 30 days).

Medicine Hat

Side by side with Lethbridge (the nearest), Gujranwala (the world's worst on 30 days).

Use this page

SmogRank, PM2.5 daily means compared, Castlegar and Medicine Hat, 7 Oct 2025 – 6 Oct 2026, smogrank.com/compare/ca-castlegar/ca-medicine-hat (accessed 7 Oct 2026).

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.

The same rules as every SmogRank figure: reference monitors first, and a day counts with 18 measured hours. How we measure.

Updated 2026-10-07 08:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index.