Is the air quality good in Delhi?
On December 28, 2025, at 8 AM PT, Delhi, India, is experiencing "hazardous" air quality with an AQI of 530.
More than 150 flights were delayed at Indira Gandhi International Airport in New Delhi, the capital district of Delhi, due to dense fog and poor visibility (1).
Air quality is dynamic and can change rapidly. Delhi ranked as the most polluted major city on Sunday morning (local time). Cities across India have been affected by poor air quality for days, particularly in the north where air quality levels have ranged from "unhealthy for sensitive groups" to "hazardous."
Click here for a real-time air quality map of Delhi.
Today’s air quality conditions are much worse than the average PM2.5 concentration for Delhi in 2024, was 108.3. This corresponds with an AQI of 188, in the “unhealthy” range, and was more than 21 times the WHO annual guideline of 5 µg/m3.
Delhi, India ranked as the most polluted major city on December 28, 2025. Source: IQAir.
When will air quality improve in Delhi?
Air quality in Delhi is expected to remain in the "hazardous" to "unhealthy" range over the next few days due to persistent winter weather conditions, including low wind speeds and dense fog (2).
Hourly air quality forecast for Delhi, India on December 28, 2025. Source: IQAir.
Forecasts suggest that meaningful improvement may occur only when wind speeds increase and weather conditions change sufficiently to disperse trapped pollutants (3). Until then, authorities continue to enforce emergency pollution-control measures under the Graded Response Action Plan (4).
Air quality map of Delhi, India on December 28, 2025. Source: IQAir.
What is causing poor air quality in Delhi?
Poor air quality in Delhi is driven by a combination of meteorological conditions and pollution sources that intensify during winter months.
- Heavy vehicle emissions from dense traffic, especially diesel-powered trucks and buses operating within and around the city (5).
- Industrial pollution from factories and power plants in Delhi and neighboring regions, releasing particulate matter and harmful gases.
- Construction dust from ongoing infrastructure projects, roadwork, and real estate development across the urban area (6).
- Seasonal crop residue burning in nearby states such as Punjab and Haryana, which sends large volumes of smoke toward Delhi during the post-monsoon period.
- Winter meteorological conditions, including temperature inversions, calm winds, and dense fog, which trap pollutants near the surface and intensify smog.
- Regional and cross-border pollution transported from other parts of the Indo-Gangetic Plain, compounding local emission sources and worsening overall air quality.
How can I protect myself from poor air quality?
- Get a free air quality app for real-time air quality alerts and forecasts.
- Shut doors and windows and set the HVAC to recirculate mode.
- Contribute to your community’s outdoor air quality data.
- Stay indoors when air quality is poor; if you do need to go outdoors, wear a KN95/FFP2 mask.
- Run a high-performance air purifier to filter particles, gases, and other pollutants.
