Bad air, but bad with what

The headline index hides which pollutant is doing the damage.

Embed this viewCheck freshness

Data access

Use the machine-readable JSON record or the flattened CSV download or the compact Markdown version.

Methodology

Median Daily Air Quality Index across every reporting LondonAir site, held separately per pollutant. The single headline figure is each site's worst pollutant, which answers whether the air is bad and hides what it is bad with. Nitrogen dioxide is largely a traffic story and PM2.5 largely a weather one; they neither peak together nor in the same places.

Provenance

Source
LondonAir
Cadence
live
Engine
live-feed

Keep going