SmogRank / World / South America / Chile / Biobio

Most polluted cities in Biobio, Chile

13 measured cities, last 30 days; 13 above the WHO 24-hour guideline. Worst: Hualpén at 38.0 µg/m³, #67 in the world.

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.

Maule Region: 4 measured citiesÑuble: 2 measured citiesAraucania: 2 measured citiesBiobio: 13 measured cities#13 Concepción: 17.7 µg/m³#12 Chiguayante: 18.5 µg/m³#11 Talcahuano: 20.3 µg/m³#10 Tomé: 20.4 µg/m³#9 Lota: 20.5 µg/m³#8 San Pedro de la Paz: 21.2 µg/m³#7 Coronel: 22.3 µg/m³#6 Los Ángeles: 23.7 µg/m³#5 Hualqui: 27.0 µg/m³#4 Laja: 29.8 µg/m³#3 Nacimiento: 31.3 µg/m³#2 Curanilahue: 32.0 µg/m³#1 Hualpén: 38.0 µg/m³
Each dot is a measured city, coloured by its PM2.5; tap a dot to open the city.
← Hualpén 53% 50%0
Every measured city in Biobio, Chile, 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. 1Hualpén 53%
  2. 2Nacimientolast full day 30 Sept 28%
  3. 3Curanilahue 27%
  4. 4Lajalast full day 30 Sept 26%
  5. 5Hualqui 20%
  6. 6Los Ángeles 7%
  7. 7Talcahuano 7%
  8. 8San Pedro de la Paz 3%
  9. 9Coronel 0%
  10. 10Lota 0%
  11. 11Tomé 0%
  12. 12Chiguayante 0%
  13. 13Concepción 0%
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

Estimated: cities without a monitor

Biobio cities we can't measure, with model estimates for the last 7 days. Listed by population, not ranked: estimates aren't precise enough to rank. Model estimates from the Copernicus Atmosphere Monitoring Service (CAMS), adjusted to measured cities nearby where there are any. Adjusted, a single day lands within ×1.5 of what a monitor would read about two times in three; unadjusted, it can be off by half or double. Treat them as a guide, not a measurement.

City7-day estimateBand
Villa Mercedes≈ 12 µg/m³Moderate
Penco≈ 20 µg/m³Moderate
Cañete≈ 12 µg/m³Moderate
Cabrero≈ 17 µg/m³Moderate
Mulchén≈ 16 µg/m³Moderate
Arauco≈ 16 µg/m³Moderate
Lebu≈ 17 µg/m³Moderate
Los Álamos≈ 17 µg/m³Moderate

Bad-air episodes in Biobio

Times when many cities around here had PM2.5 at twice their usual or more on the same days.

Use this board

SmogRank, most polluted cities in Biobio, Chile, PM2.5, last 30 days to 6 Oct 2026, 22:00 UTC, smogrank.com/cl/region/biobio?w=30d.

Download top 10 (PNG)

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.

Updated 2026-10-06 22:07 UTC. Values are PM2.5 (fine particles), the median of each city's monitors, as the US AQI PM2.5 sub-index.