Brace for colder days, minimum temperature may dip again in Delhi: IMD | Latest News Delhi

The Capital recorded yet another chilly and grey day, with the maximum temperature remaining below the normal on Sunday as icy-cold winds blew across the city. Overcast skies kept the maximum temperature at 18°C, two notches below the normal for this time of the year and higher than 15.8°C recorded a day earlier. The India Meteorological Department (IMD) has forecast the maximum to remain below normal till December 31, hovering around the 18°C mark, and a sharp dip in the minimum temperature by the year-end, as nights become colder again. It also issued a yellow alert for moderate to dense fog in the region till January 1.

On Sunday, Delhi recorded a minimum temperature of 13°C, which was six degrees above the normal, up slightly from 12.7°C recorded a day earlier and two degrees up from 11°C recorded on Friday. IMD said the minimum temperature is likely to dip to 9°C by Monday and further to 7°C by Tuesday as cold wave conditions return to isolated parts of northwest India again.

“Although a cold wave is unlikely in Delhi, the minimum will still dip by around 5-6°C as cold northwesterly winds persist in the region following rain and fresh snowfall. Cold wave conditions are likely in isolated pockets of Punjab and Haryana-Chandigarh from December 31 till January 2,” an IMD official said.

IMD classifies it as a cold wave when the minimum temperature is below 10°C, with its departure being 4.5°C or more below normal.

The official said “moderate” fog was recorded in the city in the early hours of Sunday, with the lowest visibility recorded at 350 metres at the Palam observatory at 9am. IMD defines “shallow” fog in a region when visibility drops to 500-1,000m, “moderate” fog when visibility is 200-500m, “dense” fog when visibility is 50-200m, and “very dense” when visibility dips to 50m or lower.

Weather experts said Delhi recorded higher-than-normal minimum temperatures over the past few days, largely due to cloudiness, which helps in trapping surface heat at night.

“The impact of the prevailing western disturbance, which was leading to cloudiness and rain is weakening. We are likely to see clear skies from December 30, which will lead to a dip in minimum temperature too. At the same time, cold northwesterly winds are likely, which will further help in keeping the chill factor intact even during the day. This will mean even with sunshine, the maximum will not rise too much,” said Mahesh Palawat, vice president at Skymet meteorology.

The lowest minimum temperature across the city on Sunday was 11.1°C, recorded at the Palam observatory. The lowest maximum temperature was 14.1°C, which was recorded at the Najafgarh station.

The impact of a western disturbance saw Delhi record 9mm of rainfall on December 27 and another 41.2mm on December 28, which was historically Delhi’s second wettest day in December. The only time Delhi recorded more rainfall in a single day in December was on December 3, 1923, when it was 75.7mm. The rainfall also saw Delhi record a season-low maximum temperature of 14.6°C on December 27, which was six degrees below normal.

Overall, 53.5mm of rainfall has been recorded this month, with the Capital set to end it as the fifth wettest December since 1901.

Palawat said a fresh western disturbance is likely from January 2, which is likely to bring back moisture and cloudiness, thus raising mercury again. “This dip in minimum temperature will also not sustain for too long. Thus, recording a minimum below 5°C in Delhi is unlikely,” he said.

AQI deteriorates, back to ‘poor’

Delhi’s air quality returned to the “poor” category on Sunday, with a 24-hour average air quality index (AQI) of 225 recorded at 4pm. The average AQI was 139 (“moderate”) at the same time on Saturday, aided by rainfall in the past 24 hours. Delhi’s AQI was 353 (“very poor”) on Friday, marking sharp variations in 24-hour spans.

“The AQI improved as the rain helped settle pollutants. However, that impact was temporary and with no rain recorded in the past 24 hours, background pollution is beginning to spike again,” Palawat said.

Forecasts by the Early Warning System for Delhi (EWS) predicted the AQI to worsen further by Monday due to an expected dip in temperatures.

“Delhi’s air quality is likely to be in the ‘very poor’ category from December 30 till January 1,” EWS said in its bulletin.