Delhi may see rain today and tomorrow, temp to fall: IMD

The rain is also expected to have an impact on Delhi’s maximum and minimum temperature this week – having a cooling effect.

Delhi and the National Capital Region (NCR) will be impacted by the strong western disturbance prevailing across northwest India from Monday onwards while the India Meteorological Department (IMD) has issued a yellow alert for multiple spells of light to moderate rain across the city on Monday and Tuesday.

Delhi’s maximum on Sunday was recorded at 34.1°C. (Vipin Kumar/HT Photo)

Subsequently, the cold northwesterly winds will lead to a drop in minimum temperature from Wednesday onwards, the IMD said.

“Heavy to very heavy rains are expected in some parts of the plains and mountains. In the upper reaches, snowfall is also likely on Monday,” Krishna Kumar Mishra, senior Scientist at IMD’s regional weather forecasting centre in Delhi, said. The western disturbance is fairly active and currently bringing moisture from the Arabian sea, he said, adding that once the disturbance departs, cold northwesterly winds will return, leading to a slight chill in the air.

With just five days into the month, Delhi’s October rain is already in “excess”. Safdarjung, the base station for Delhi’s weather, has received 51.8mm so far – over three times the monthly normal of 15.1mm. Last October, Delhi recorded zero rainfall. Expected showers on Monday and Tuesday will also add to this total, pushing the rainfall closer to 100mm this month.

Excess rains have been dominant in the region since May. This May was the wettest ever on record with 186.4mm of rainfall, over six times the normal of 30.7mm.

In June, Delhi recorded 107.1mm of monthly rainfall, an excess of 45% over the long period average (LPA) of 74.1mm. In July, Delhi received 259.3mm of rainfall, which was 24% more than the LPA of 209.7mm. August meanwhile was the wettest in 15 years, with 400.1mm logged — an excess of 72% over the LPA of 233.1mm. Last month saw 136.1mm being recorded, 10% over the monthly normal of 123.5mm in September.

This year, monsoon withdrawal was declared on September 24, the earliest in Delhi since 2002, when it departed on September 20. Last year, the monsoon retreat was recorded on October 2.

The rain is also expected to have an impact on Delhi’s maximum and minimum temperature this week – having a cooling effect.

Delhi’s maximum on Sunday was recorded at 34.1 degrees Celsius (°C), which is around normal for the season. This is forecast to dip to around 28°C on Monday. The minimum meanwhile stood at 24.2°C – two degrees above normal. This can fall to around 20°C by Wednesday, as cooler, northwesterly winds return.

“This western disturbance will have a cooling effect. The upper Himalayas may see some snow, with other parts expected to see rain and hailstorm. These cold and dry winds will then blow from the mountains towards the plains, having a cooling effect in NCR from October 8 and 9 onwards,” said Mahesh Palawat, vice president at Skymet.

Delhi’s air quality, meanwhile, deteriorated to the higher end of the “moderate” category on Sunday. The 24-hour average air quality index (AQI) stood at 159 (moderate) at 4pm, as against 138 (moderate) on Saturday and 88 (satisfactory) on Friday. Forecasts by the Centre’s Air Quality Early Warning System (EWS) for Delhi shows AQI is likely to return to “satisfactory” by Monday.

According to the Central Pollution Control Board (CPCB), an AQI between zero and 50 is considered “good”, between 51 and 100 “satisfactory”, 101 and 200 “moderate”, 201 and 300 “poor”, 301 and 400 “very poor”, and 401 and 500 “severe”.