Imperial Beach vs Mecca: PM2.5 compared

Over the last year, Imperial Beach and Mecca had about the same air: PM2.5 averaged 11.8 and 12.1 µg/m³, on the 80 days both cities were measured. Imperial Beach had the dirtier air on 46 of those days, Mecca on 34. Imperial Beach was over the WHO's daily guideline of 15 µg/m³ on 17 of them, Mecca on 25.

Right now

Imperial Beach#252on the 24-hour board of 2,002, at 63 US AQI (15.4 µg/m³)

Mecca#87on the 24-hour board of 2,002, at 77 US AQI (23.1 µg/m³)

The last year, day by day

Imperial Beach

Mecca

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

Monthly means in µg/m³ over the days both cities were measured. Solid: Imperial Beach. Faded: Mecca. A month shows once both share 10 such days. Dashed line: the WHO daily guideline, 15 µg/m³.

Each city's worst days

Imperial Beach

17 May 20268828.9 µg/m³
20 May 20268426.6 µg/m³
21 May 20267521.8 µg/m³

Mecca

21 May 202614854.6 µg/m³
16 May 202613047.2 µg/m³
18 May 20269733.8 µg/m³

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

Imperial Beach

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

Mecca

Side by side with Indio (the nearest), Hanford (United States's 2nd worst on 30 days), Gujranwala (the world's worst on 30 days).

Use this page

SmogRank, PM2.5 daily means compared, Imperial Beach and Mecca, 7 Oct 2025 – 6 Oct 2026, smogrank.com/compare/us-imperial-beach/us-mecca (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.