Delhi Weather Today | Visibility Drops As Dense Fog Blankets Delhi-NCR, Orange Alert Issued Dense fog has engulfed Delhi-NCR, severely reducing visibility and disrupting normal life. The IMD has issued an orange alert for the region, while airlines including IndiGo, Air India and SpiceJet have warned of possible flight disruptions. Delhi's air quality has deteriorated to the 'severe' category, prompting Delhi Airport to issue a travel advisory. The IMD has also issued fog alerts for parts of Uttar Pradesh and Himachal Pradesh.