Delhi AQI turns poor for first time since July; very poor forecast

Delhi AQI slipped into the "poor" category on Wednesday, October 21, 2026, the first poor reading of the season, and forecasts show it worsening to "very poor" by Thursday. The Air Quality Early Warning System, run by the Indian Institute of Tropical Meteorology (IITM) Pune with the India Meteorological Department (IMD), showed Delhi's Air Quality Index (AQI) at 219 at 7 am, while another reading at 7.05 am put it at 227. Two monitoring stations, Jahangirpuri and Pusa, were already in the very poor band at 308 and 314.

Delhi's air tends to worsen after the monsoon, when conditions for dispersing pollution weaken. The first poor reading of the season is usually the point at which the city's air stops being a background issue and starts shaping daily life. This year it arrived on October 21, three months after the last poor day in July.

For young people who exercise outdoors, the timing matters most. Early morning is when many students and young professionals run, cycle or play in parks before college or work. It is also when readings were taken today, with the city average above 200 and two stations above 300. The AQI is a single number built from the levels of several pollutants, such as fine particles (PM2.5 and PM10), and it is grouped into bands that run from "good" to "severe". The CPCB's own description of each band is the clearest guide to what a number means. In the poor band it describes breathing discomfort to most people on prolonged exposure; in the very poor band it warns of respiratory illness on prolonged exposure. Prolonged exposure is the key phrase. A long outdoor run, during which a person breathes faster and more deeply for an hour or more, is a longer and heavier exposure than a short walk to the bus stop.

The forecast is the reason to pay attention now rather than later. The early warning system expects the AQI to reach 342 on Thursday morning, inside the very poor band. Readings also differ across the city: Jahangirpuri and Pusa were in the very poor range while the city average was still in the poor range. A runner in one neighbourhood may be breathing very different air from a friend a few kilometres away. Checking the nearest monitoring station, rather than only the city average, gives a truer picture.

Short-term: With the forecast pointing to the very poor band on Thursday, outdoor workouts, morning runs, school and college sports, and weekend cycling groups in Delhi are likely to be held in worse air over the coming days. Young people with asthma or other lung conditions are the most exposed and should follow the advice of their own doctors.

Long-term: If the air stays in the poor and very poor bands, it is likely to push more young people towards indoor gyms, earlier or later workout times when air may be cleaner, and closer attention to the daily AQI, and to keep pressure on the authorities to act on the sources of pollution.

Who is affected: Everyone in Delhi and the National Capital Region, but especially those who exercise or work outdoors, students who play sport, delivery workers and riders, and people with asthma, lung or heart conditions.

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