SmogRank / World / United Kingdom / Wales / October 2026

Most unhealthy days in Wales, United Kingdom, October 2026

4 cities in Wales, United Kingdom ranked by their share of unhealthy days so far (7 of 31 days). The most unhealthy days: Swansea, United Kingdom, 0 of 7 measured days. A city needs measurements on 70% of the days to be ranked.

Ranked by unhealthy days: the share of each city's measured days with a daily mean over 35.4 µg/m³ (US AQI 101+), Unhealthy for Sensitive Groups or worse on the US EPA's scale. Ties go to the higher average.

← Swansea 0% 0.75%0
Every city in Wales, United Kingdom ranked for October 2026, one column each, ranked by unhealthy days: height is the share of its measured days that were unhealthy, colour its average. Point at it to read a city; tap to open it.
  1. 1Swansea
    0 of 7
  2. 2Cardiff
    0 of 7
  3. 3Newport
    0 of 7
  4. 4Wrexham
    0 of 7
Good0–50
Moderate51–100
Sensitive groups101–150
Unhealthy151–200
Very unhealthy201–300
Hazardous301+

The US EPA's Air Quality Index for PM2.5 (2024 breakpoints). Show values as: µg/m³ · US AQI · India AQI · China AQI · European AQI · UK DAQI · Canada AQHI+. About the scales

All cities in the world, October 2026 · All cities in United Kingdom, October 2026 · Wales now

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SmogRank, most polluted cities in Wales, United Kingdom, by unhealthy days, PM2.5, October 2026 (so far), smogrank.com/gb/region/wales/history/2026-10?by=days (accessed 8 Oct 2026). Some readings from Uzhydromet (Uzbekistan's Hydrometeorological Service); Department of Environment, Nepal; Vietnam's government monitors; Aurassure; Umhverfisstofnun (Environment Agency of Iceland); Love My Air (City and County of Denver), no reuse terms published.

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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.