Delhi Air Quality Improves Amid Strong Winds and Persistent Fog

Delhi experienced a temporary relief from its severe pollution levels on Wednesday morning, thanks to strong surface winds. The air quality index (AQI) was noted at 342, categorised as 'very poor', by 8am, according to the Central Pollution Control Board. This was a notable improvement from the previous evening's 24-hour average AQI of 412, which classified the air quality as 'severe'. This marked the fourth day of severe air quality in Delhi for the month.

The Air Quality Early Warning System (AQEWS) has indicated that the AQI is expected to remain in the 'very poor' range throughout the day. "The air quality is likely to remain in the very poor category from Wednesday to Friday. The outlook for the subsequent six days suggests continued very poor air quality," stated a bulletin from the AQEWS.

In addition to the pollution concerns, a shallow to moderate fog blanketed various regions of the city. Visibility levels at Palam Airport dropped to 100 metres at 2.30am, improving slightly to 250 metres by 6.30am. Although no flight cancellations were reported at Delhi airport, data from Flightradar24 indicated that over 150 flights were delayed as of 8am.

The India Meteorological Department (IMD) classifies fog based on visibility: shallow fog is noted when visibility ranges from 500 metres to 1,000 metres, moderate fog is defined as visibility between 200 metres and 500 metres, dense fog is when visibility is between 50 metres and 200 metres, and very dense fog occurs when visibility falls below 50 metres.

The IMD has predicted similar weather patterns to persist. An official stated, "Strong surface winds with speeds of 15-25 kilometres per hour will affect the region on Wednesday. Shallow to moderate fog is expected to continue on Thursday as well." The IMD has also issued a yellow alert for Friday, anticipating moderate to dense fog during the morning hours.

Temperature forecasts suggest a further decline over the Christmas weekend, contributing to the ongoing challenges posed by both pollution and fog in the capital city.