Delhi’s air pollution has risen sharply through October and reached its worst levels this week. Over five days, AQI readings fluctuated from dangerous to extreme, with a peak of over 700 in the morning. On November 14, Delhi recorded a 24-hour average AQI of 399, one point below the severe category. Meteorologists cite light winds, low temperatures, and temperature inversion as factors that trap pollutants. Stage Three restrictions are in place, but conditions remain hazardous. Rising pollution has also led to a surge in air purifier and mask sales.