Delhi: Mercury dips to season's low, pollution up

The minimum temperature at Safdarjung, Delhi’s base station, on Thursday was a notch below normal, and lower than the previous day’s recording of 10.1°C.

The minimum temperature in Delhi on Thursday fell to a season-low of 8.4 degrees Celsius, showed data from the central weather office, as clear skies paved the way for cooler days and nights.

Pigeons take flight on a foggy morning in the outskirts of Dwarka in New Delhi. (Vipin Kumar / HT Photo)

The pollution levels too stayed in the ‘poor’ zone for the second straight day, though forecasters did warn that the air quality may worsen marginally this week.

The minimum temperature at Safdarjung, Delhi’s base station, on Thursday was a notch below normal, and lower than the previous day’s recording of 10.1°C.

The maximum temperature in the Capital, meanwhile, was 23.5°C, one below normal, and down marginally from 24°C on Wednesday.

Weather forecasters said that cloudy skies in Delhi over the past few days kept temperatures from dipping, adding that clearer skies over the coming week will see the mercury fall further.

“When you have cloudy skies, the heat from the surface gets trapped and cooling does not happen at a fast rate. Now that Delhi is likely to have clearer skies the minimum temperatures will remain around 7-8°C,” said Mahesh Palawat, vice-president (meteorology and climate change), Skymet Weather Services.

He added that heavy snowfall in parts of Himachal Pradesh, Uttarakhand and Jammu & Kashmir played their part in reducing Delhi’s mercury.

“Delhi has been receiving consistent winds from the northwest. Since there has been heavy snowfall in parts of Himachal Pradesh, J&K and Uttarakhand, colder winds from there are helping bring down the temperatures,” he said.

Owing to the cloud cover over the city for much of the month, Delhi has so far this December been warmer than normal, according to data from the India Meteorological Department (IMD).

The minimum temperature has oscillated between 10-12°C over the last week, and on December 5, it rose to 15°C (three above normal).

And while clear skies helped keep the city’s pollution levels in the ‘poor’ zone on Thursday, they did increase marginally from the previous day, showed recordings from the Central Pollution Control Board (CPCB).

Delhi’s 24-hour average air quality index (AQI) rose to 289 on Thursday, from 237 on Wednesday.

An AQI between zero and 50 is considered good, 51 and 100 satisfactory, 101 and 200 moderate, 201 and 300 poor, 301 and 400 very poor, and 401 and 500 severe.

Forecasts said that they air is likely to worsen on Friday.

“The air quality over Delhi is likely to deteriorate marginally but remain in poor to lower end of very poor category owing to slow wind speed. No major deterioration in air quality is forecast for the next two days,” the pollution forecast by the Union ministry of earth sciences’ early warning system read