Mercury has been plummeting consistently for the last 4 days, surpassing previous day's minimum temperature. Official observatory of Delhi at Safdarjung today recorded minimum temperature of 6.4 degree celsius, about 3 degree below the average. It has overtaken previous day minimum of 8.3 degree.
Minimum temperature invariably take a large dip around last week of December.
Defying norms, the temperature in single digit has been recorded for the 4th day in a row. It has resulted sharp and punching chill in the air, akin to mild cold wave conditions. Last 3 consecutive years have recorded lowest of about 3 degree in the month of December. Lowest monthly temperature of December was 3.3deg, 2.4deg and 2.6deg celsius on 31Dec 2020, 28Dec 2019 and 29Dec2018, respectively.
Single digit temperatures for 4 days in a row is not very common during 1st half of the month. There is no active western disturbance expected in the next one week or so. However, feeble dry cyclonic circulation is coming up over central parts of Rajasthan. This will change the wind pattern to mainly easterly over and around NCR, for the next about 48hr, in the lower levels of atmosphere.
Accordingly, the minimum temperature is not expected to drop further for the time being. This circulation is likely to shift and get filled up subsequently. Normal cold and dry northwesterly winds will resume from 15th December onward. The minimum temperature will once again take a dip around that time. Temperature dropping to 5-6deg during the next week remains a possibility.