Mecca vs Upper Alton: PM2.5 compared

Over the last year, Mecca's air was about 1.7× as polluted as Upper Alton's: PM2.5 averaged 12.1 µg/m³ against 7.0, on the 80 days both cities were measured. Mecca had the dirtier air on 58 of those days, Upper Alton on 22. Mecca was over the WHO's daily guideline of 15 µg/m³ on 25 of them, Upper Alton on 1.

Right now

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

Upper Alton#566on the 24-hour board of 2,002, at 52 US AQI (9.8 µg/m³)

The last year, day by day

Mecca

Upper Alton

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: Mecca. Faded: Upper Alton. A month shows once both share 10 such days. Dashed line: the WHO daily guideline, 15 µg/m³.

Each city's worst days

Mecca

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

Upper Alton

17 Sept 20266416.0 µg/m³
18 Sept 20266114.4 µg/m³
19 Sept 20266114.2 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

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).

Upper Alton

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

Use this page

SmogRank, PM2.5 daily means compared, Mecca and Upper Alton, 7 Oct 2025 – 6 Oct 2026, smogrank.com/compare/us-mecca/us-upper-alton (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.