A toxic haze enveloped India's national capital on Wednesday morning as temperatures dropped and pollution surged, reducing visibility in some parts and prompting a warning from airport authorities that flights may be affected.

Every year, Delhi and northern states battle hazardous air during the winter months of October to January due to plummeting temperatures, smoke, dust, low wind speed, vehicular emissions and crop stubble burning. This time, experts say that the condition is likely to get worse in the coming days.

Delhi typically sees a spike in air pollution during the festive season starting in October. After Dussehra celebrations in the second week of October, Delhi’s Air Quality Index

New Delhi topped global pollution charts on Friday, partly due to revellers defying a ban on firecrackers to celebrate Diwali, the Hindu festival of lights.

Delhi AQI soared to 452 by 11pm, falling in comfortably “severe plus” – the worst possible category within the AQI range

Delhi's air quality turned 'severe' for the first time this season on Wednesday, with the AQI soaring to 418. In comparison, the national capital's 24-hour average Air Quality Index (AQI) -- recorded at 4 pm every day -- stood at 334 on Tuesday.