More rain in store for Delhi this week

Delhi may see light rain this week with temperatures below 20°C. Air quality remains "poor," while dense fog persists.

The Capital is likely to get more rain this week with a fresh western disturbance expected to influence parts of northwest India from Tuesday onwards. The India Meteorological Department (IMD) has forecast chances of light rain in Delhi on Wednesday and Thursday, keeping skies overcast and the daytime temperature below 20 degrees Celsius (°C).

Blue skies over Vasudev Ghat on the Yamuna in north Delhi on Monday. (Arvind Yadav/HT Photo)

Delhi’s air quality remained in the “poor” category on Monday while improving in the past 24 hours. The average air quality index (AQI) was 248 (poor) at 4pm as compared to 278 (poor) at the same time on Sunday. The Commission for Air Quality Management (CAQM) had lifted Stage 3 measures of the Graded Response Action Plan (Grap) on Monday. Separately, in neighbouring NCR cities, Gurugram logged a “moderate” AQI of 156 on Monday, precisely the same as of Sunday. In contrast, Noida, Greater Noida and Ghaziabad on Monday saw “moderate” AQI readings of 168, 174, and 160, respectively, compared to 192, 144, and 186, on Sunday.

Delhi reported dense fog on Monday. “The lowest visibility in the city was 50 metres at Palam from 4.30am till 8am. At Safdarjung, it was 150 metres between 5.30am and 6.30am,” said an IMD official, forecasting similar intensity fog in the next 48 hours.

IMD has an orange alert in place for Tuesday forecasting dense to very dense fog in the region. For Wednesday, IMD has issued a yellow alert for Wednesday for possibility of very light rain. IMD classifies visibility between 50 and 200 metres as “dense” fog and below 50 is “very dense”. “There is a chance of drizzle in parts of Delhi on Wednesday night and in the early hours of Thursday due to an approaching western disturbance,” said the official.

While no flights were diverted or cancelled at the Delhi airport, some flights were delayed. The Northern Railways said at least 12 trains were delayed by more than 30 minutes due to the weather.

On Monday, the Capital logged a minimum temperature of 9.4°C on Monday, two degrees above normal and a slight rise from 9°C a day earlier. It is expected to drop to around 7°C by Wednesday before rising again. Delhi’s maximum temperature on Monday was at 18.5°C, which was a degree below normal. It was 17.3°C a day earlier. The maximum is likely to hover between 18-19°C till Thursday, IMD officials said.

Separately, Gurugram saw a minimum temperature of 10.5°C on Monday. Greater Budh Nagar, comprising of Noida, and Greater Noida, meanwhile, recorded a minimum temperature of 10.3°C, with the maximum at 19.7°C.

“While we expect light rain in the plains and some snowfall, we are not seeing a sharp dip in temperature as back-to-back western disturbances are being recorded. This changes the wind direction, not allowing cold northwesterly winds to persist,” said Mahesh Palawat, vice president at Skymet.

Strong winds and rain both help Delhi’s AQI, allowing pollutants to either disperse or settle. Forecasts show winds are expected to slow down on Tuesday with the approaching western disturbance, which will likely push AQI into the “very poor” category (over 300) again.

In its rainfall forecast for the first three months of the year, IMD on January 1 had said that north India was most likely to record below normal rainfall (<86% of LPA) till March 31. However, the seasonal rainfall over the country as a whole is expected to be around normal during these three months (88-112% of LPA).

In January specifically, north India is likely to see above normal rainfall (>122 % of LPA), IMD had said. Delhi has recorded 2.2mm of rainfall this month. The long-period average (LPA) for January rainfall is 19.1mm.