Frigid conditions to persist as Delhi records lowest day temperature since 2020; light rain likely

New Delhi, Dec 31 (PTI) A biting chill gripped the capital on Wednesday as "cold day" conditions prevailed, while a thick shroud of fog descended over the city, with air quality in the 'very poor' category.

The India Meteorological Department (IMD) said the maximum temperature settled at 14.2 degrees Celsius, 6.2 degrees below normal and the lowest day temperature recorded since 2020.

Station-wise data showed that Palam logged 13.6 degrees Celsius, Lodhi Road 13.4 degrees Celsius, the Ridge 13.8 degrees Celsius and Ayanagar 13.1 degrees Celsius.

The minimum temperature was recorded at 6.4 degrees Celsius, 0.4 degrees Celsius below normal. Palam station logged a minimum of 7.7 degrees Celsius, Lodhi Road 6.8 degrees Celsius, and the Ridge 7.8 degrees Celsius, according to the IMD.

A generally cloudy sky with light rain is forecast for January 1, with cold day conditions expected to continue.

"A cold day is declared when the minimum temperature falls below 10 degrees Celsius and the maximum temperature remains about 4.5 degrees below normal," an IMD official said.

"There is a slight chance of very light and isolated rain over Delhi and the NCR between tonight and New Year's Day due to an induced cyclonic circulation over Punjab and Haryana. If it occurs, this could be the season's first spell of rain," Mahesh Palawat of Skymet told PTI.

From January 3, coldwave conditions may develop as the minimum temperature could drop below 5 degrees Celsius, with cold northerly winds from the Himalayan region expected to move towards the capital, he added.

Meanwhile, visibility dropped sharply in several parts of the city due to dense fog on Wednesday.

According to the weather department, Safdarjung reported the lowest visibility of 50 metres between 6.30 am and 7.30 am, which later improved to 100 metres by 8 am. Palam recorded visibility as low as 50 metres between 4 am and 7.30 am, improving to 150 metres by 8 am.

IMD scientist Dr Naresh Kumar said dense to very dense fog has been prevailing over north India for nearly two weeks. "Dense fog may occur at isolated places in Delhi tomorrow morning," he said.

Explaining the weather pattern, Kumar said an active western disturbance is currently positioned over north Pakistan. "Due to its influence, light to moderate rainfall and snowfall will continue over the western Himalayan region for the next two to three days. Very light rainfall activity is also possible over the NCR region," he said.

He explained that fog forms when temperatures are low, winds are light and moisture levels are high. "When these conditions persist, fog stays longer during the day, blocks sunlight and helps cold day conditions continue," he said.

The IMD said dense to very dense fog is likely to persist in Delhi for the next five days.

For the New Year's Day, the IMD forecast generally cloudy skies with a possibility of very light to light rain at isolated places. Shallow to moderate fog is expected during the morning hours, with maximum temperatures likely to remain between 14 degrees Celsius and 16 degrees Celsius and minimum temperatures between 9 degrees Celsius and 11 degrees Celsius.

Meanwhile, air quality readings remained in the 'very poor' range across the city. The 24-hour average Air Quality Index (AQI) stood at 373.

A station-wise analysis showed that 23 monitoring stations recorded 'very poor' air quality, while 14 stations were in the 'severe' category. ITO recorded the worst AQI at 433 during the evening hours, according to CPCB's SAMEER app.

During morning hours, the capital recorded an AQI of 384. Station-wise data showed that 21 monitoring stations recorded 'very poor' air quality, while 16 stations were in the 'severe' category, with Anand Vihar registering the worst AQI at 452, according to the CPCB.

According to Central Pollution Control Board (CPCB) standards, an AQI between 0 and 50 is considered 'good', 51 to 100 'satisfactory', 101 to 200 'moderate', 201 to 300 'poor', 301 to 400 'very poor' and 401 to 500 'severe'.

Officials attributed the poor air quality to an unfavourable ventilation index of below 6,000 square metres per second and average wind speeds below 10 kmph, not conducive to the dispersion of pollutants.

According to the Air Quality Early Warning System, the AQI is likely to remain in the 'very poor' category until January 3. The forecast for the subsequent six days also indicates 'very poor' air quality.

Officials said category-wise source contribution data from the Decision Support System (DSS) was not uploaded till 6 pm on Wednesday.

On Tuesday, the AQI stood at 388, showing a marginal improvement from Monday, when the city recorded 'severe' air quality with average AQI logged at 401. PTI SGV SGV ARB ARB