Delhi air quality: frequently asked questions
Answers that quote live figures update with each hourly reading.
What is Delhi's AQI now, and what does the category mean?
As of 11:00 IST on 23 October 2026, Delhi's AQI is 224 (Poor) on India's National AQI scale. 56 of 60 stations are reporting, and PM2.5 is the lead pollutant at 45 of them. The AQI is 4 points higher than at the same hour yesterday. "Poor" means: Breathing discomfort to most people on prolonged exposure.
Live AQI on the home page →Which stations are highest right now?
At 11:00 IST on 23 October 2026, the highest AQI is at R K Puram (286), Pusa (286), Pusa (282). Every station is listed on the stations page.
All monitoring stations →How does today compare with yesterday?
Delhi's AQI is 4 points higher (worse) than at the same hour yesterday. To compare each station with an earlier reading, use "Compare with earlier" on the stations page.
What are PM2.5 and PM10?
PM2.5 and PM10 are particles in the air smaller than 2.5 and 10 micrometres across. PM10 includes road and construction dust; PM2.5 comes mostly from combustion, such as vehicles, industry and the burning of waste and crop residue, and can reach deep into the lungs. Both are measured in micrograms per cubic metre (µg/m³).
How is India's AQI calculated, and how does it differ from the US AQI?
Each station measures up to eight pollutants (PM2.5, PM10, NO₂, SO₂, CO, O₃, NH₃ and Pb). Each concentration is converted to a sub-index, and the station's AQI is the highest sub-index, provided at least three pollutants, including PM2.5 or PM10, are available. Delhi's AQI on this site is the average of the reporting stations. The US AQI uses different breakpoints, so the two numbers cannot be compared directly.
About the AQI →How often are readings updated?
Stations report every hour. This site checks for a new reading every few minutes and shows the hour each value is for. A station with no reading in the last 2 hours is shown as not reporting rather than with an old value.
Why do stations differ?
Each station measures the air around it. Traffic junctions, industrial areas, construction, waste burning and open dusty land raise local readings, while green or residential areas are often lower. Wind, temperature and the time of day also change how pollution builds up across the city.
What GRAP stage is in force?
According to the live feed, the GRAP status is: Stage I (Poor). Stages of the Graded Response Action Plan (GRAP) are invoked by the Commission for Air Quality Management (CAQM): Stage I (AQI 201–300), Stage II (301–400), Stage III (401–450) and Stage IV (above 450). See the latest CAQM order for the restrictions in force.
CAQM orders ↗Sources: CPCB/DPCC monitoring stations (live AQI), CPCB National Air Quality Index (categories and health impacts), CAQM (GRAP). Health information is general guidance, not medical advice.