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Mercury dips to 3.6°C in parts of Delhi amid isolated cold wave conditions
An Average Air Quality Index (AQI) of 209 was recorded at 8am on Monday, compared to 153 at 4pm on Sunday, Delhi’s lowest in January in four years
The mercury dipped to 3.6°C in parts of Delhi on Monday amid isolated cold wave conditions, even as the air quality deteriorated to the “poor” category following a rare, two-day streak of “moderate” pollution levels in January. An Average Air Quality Index (AQI) of 209 was recorded at 8am on Monday, compared to 153 at 4pm on Sunday, Delhi’s lowest in January in four years.
Clear skies and sustained icy-cold northwesterly winds over the couple of days led to a further drop in temperature. A fresh western disturbance is expected to raise the mercury again and bring light showers on Tuesday.
A minimum temperature of 4.2°C, four degrees below normal, was recorded at Safdarjung, Delhi’s representative weather observatory, compared to 6.6°C on Sunday and 7.6°C on Saturday. Ayanagar observatory in southwest Delhi recorded a minimum temperature of 3.6°C, 5.4°C below normal. The mercury dipped to 5.3°C at north Delhi’s Ridge observatory, five notches below the normal.
A cold wave is when the minimum temperature is below 10°C and at least 4.5°C below normal, or when the mercury drops to 4°C or lower. At least two stations met this criterion on Monday.
A yellow alert has been issued for Tuesday for one to two spells of light rain during the day, with gusty winds of up to 40 km per hour, which should again keep Delhi’s air quality in check.
“When a western disturbance approaches, it causes a change in wind direction to warmer easterly winds. Overcast skies also lead to a rise in minimum temperature and a dip in maximum temperature,” said private forecaster Skymet Weather vice president Mahesh Palawat. He added that a fresh snowfall is again expected in the Himalayas and a dip in minimum temperature is likely across the plains from January 29.
The Air Quality Early Warning System for Delhi said the AQI is likely to return to the “moderate” range by Wednesday. The AQI will oscillate between “moderate” and “poor” between January 29 and February 3.
