Littleton vs Mecca: PM2.5 compared
Over the last year, Mecca's air was about 4.3× as polluted as Littleton's: PM2.5 averaged 12.5 µg/m³ against 2.9, on the 32 days both cities were measured. Mecca had the dirtier air on 29 of those days, Littleton on 3. Mecca was over the WHO's daily guideline of 15 µg/m³ on 13 of them, Littleton on 0.
Right now
The last year, day by day
Month by month
Each city's worst days
Littleton
- 21 Sept 2026285.1 µg/m³
- 30 Sept 2026274.8 µg/m³
- 6 Sept 2026244.3 µg/m³
Mecca
- 1 Oct 20268225.9 µg/m³
- 23 Sept 20267421.2 µg/m³
- 2 Oct 20267320.9 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
Littleton
Side by side with Ken Caryl (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, Littleton and Mecca, 7 Oct 2025 – 6 Oct 2026, smogrank.com/compare/us-littleton/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.