SmogRank / History / City race
Cities in Peru, worst air first, day by day
Each measured city's average over the 30 days to every day since January 2023, worst first. Find your own city to follow it through the race, or keep to one country.
The worst cities in Peru for PM2.5 over the 30 days to 10 Dec 2025: Santa María 48.1 µg/m³, Lima 28.7 µg/m³ and San Francisco De Borja 21.8 µg/m³.
- 1Santa MaríaLima region48.1
- 2LimaLima Province28.7
- 3San Francisco De BorjaLima region21.8
- 4CallaoCallao20.3
Not counted on this day, too few days measured: Santa Anita - Los Ficus since 2 Dec 2025 and Villa Poeta José Gálvez Barrenechea since 23 Nov 2025.
Cities counted each day
A city's number is its average over the 30 days, shown only when 21 of them were measured (5 of 7 on the 7-day race), the same minimum as the 30- and 7-day boards. A city whose monitors go quiet fades out where it stood rather than sliding down, so a gap never reads as cleaner air. Some large countries are thin or missing because their monitors' licences don't allow reuse. How we rank.
Not covered: the government monitoring networks of China and Turkey, which publish only on their own websites; we are building the readers for them. Most cities there are missing from this board, not clean. Why.