Delhi's Winter Smog

Why Delhi's air becomes dangerously polluted every October to January, how weather and stubble smoke combine, and the economic costs of the annual crisis.

Every winter, Delhi’s air turns hazardous.

Why winter

Cold air and low wind trap pollution near the ground (temperature inversion).
Stubble burning in Punjab and Haryana adds smoke in October-November.
Diwali firecrackers add a spike.
Year-round vehicles, dust and industry.

Severe levels

AQI often exceeds 400 (“severe”), sometimes much higher.

Emergency responses

Schools closed.
Construction bans.
Trucks restricted.
Under the Graded Response Action Plan (GRAP), measures tighten as AQI worsens.

Economic costs

Health spending and lost workdays.
Tourism and business travel deterred.
Productivity losses.

Recurring problem

The crisis returns annually, showing that seasonal fixes don’t address year-round sources.

The school closure

In November, Delhi schools close for days as AQI crosses 450, and parents buy air purifiers and masks.

Thinking Delhi's pollution is only from stubble

Vehicles, dust and industry contribute year-round.

Key takeaways

Delhi's air turns hazardous every winter.
Weather traps pollution; stubble smoke adds to it.
GRAP tightens measures as AQI worsens.
The crisis has large health and economic costs.