At 4.4°C, Delhi minimum falls to season’s lowest

Cold northwesterly winds on Wednesday sent Delhi’s minimum temperature to a season-low of 4.4 degrees Celsius (°C) -- three degrees below the normal for this time of the year -- with isolated parts of the Capital recording both ‘coldwave’ and ‘cold day’ conditions. Before this, the lowest minimum of the current winter season had been recorded on December 26 (5°C).

While Wednesday’s reading of 4.4°C was recorded at Safdarjung, which is representational of Delhi’s weather, the lowest minimum across the city was 3.3°C at the Ridge station.

The India Meteorological Department (IMD) declares a ‘coldwave’ in a region when the minimum temperature is 4.5 degrees or more below the normal mark, or when it drops to 4°C or lower. The reading at the Ridge station met this criteria on Wednesday.

“We are now starting to see the impact of cold northwesterly winds, which has led to a drop in the minimum temperature by around 4 degrees in Delhi. These cold winds will ensure the minimum remains around 4 degrees Celsius for the next three days, with it being even lower in other parts of the Capital,” said a met official.

Delhi’s maximum temperature too remained below normal, with a high of 16.5°C -- three degrees below normal. The IMD classifies a ‘cold’ day as when the maximum temperature is 4.5 degrees or more below normal, while the minimum is below 10°C. At stations like Jafarpur (13.2°C), Palam (14°C), and Mayur Vihar (14.1°C), the maximum was 5-6 degrees below normal.

Forecasts show Delhi’s maximum is likely to hover between 18-19°C in the next three days, while the minimum will continue to hover around the 4-degree mark.

Met officials said Delhi recorded dense fog for only a brief period on Wednesday, when visibility dipped to 200m at around 2.30am. However, visibility gradually started improving after that, with fog lifting by 8.30am.

The IMD has issued a yellow alert for Delhi for the next three days, warning of moderate to dense fog in the early hours and for coldwave conditions in isolated parts during the night.

The cold winds also led to an improvement in Delhi’s pollutions levels, with the city recording an Air Quality Index (AQI) reading of 343 (very poor) as per the daily Central Pollution Control Board (CPCB) bulletin released at 4pm. In comparison, Delhi’s average AQI reading on Tuesday was 385.

The improvement in air quality prompted the Commission for Air Quality Management (CAQM) to revoke all measures under Stage III of the Graded Response Action Plan (Grap) with immediate effect. The lifting of this ban allows private construction activities to resume across NCR, while also allowing resumption of brick kilns and hot mix plants not operating on clean fuels, resumption of operations of all stone crushers in NCR and mining and its associated activities in NCR to also resume.

The CAQM had invoked Stage III of Grap on December 30, when the city’s AQI was recorded at 399 (very poor) and was forecast to deteriorate further. However, since then, the city’s AQI has remained under the 400-mark.

Meanwhile, the Delhi Pollution Control Committee (DPCC) on Wednesday issued an advisory, asking RWAs, schools, tourist sites and private and government offices to share ‘warm kits’ with security guards so that instances of open burning could be brought down.

The advisory states each kit can consist of a sweater or a jacket, a pair of warm socks, an electric heater, gloves, a blanket and a woollen cap. It also adds that an N95 mask should be provided as part of the kit.