Overnight showers in Delhi leads to drop in temperature, more rain likely

Similar weather activity is also likely on Tuesday, with cold northwesterly winds set to lead to a drop in minimum temperature from Wednesday onwards

Delhi recorded an intense spell of rain in the early hours of Monday due to a strong western disturbance in the region. The overnight rain was accompanied by gusty winds, touching over 50 km/hr in parts of the city. The India Meteorological Department (IMD) has issued a yellow alert for ‘multiple spells’ of light to moderate showers across the city throughout Monday.

With just six days into the month, Delhi’s rain is already in ‘excess’ for October. (HT photo)

Similar weather activity is also likely on Tuesday, with cold northwesterly winds set to lead to a drop in minimum temperature from Wednesday onwards, IMD said.

Between 11:30pm on Sunday and 5:30am on Monday, Safdarjung, the city’s base station, logged 10.3mm of rainfall, IMD data showed. In the same period, Palam recorded 4.6mm, Pitampura 13.5mm, Pusa 8.5mm, Mayur Vihar 11mm and Janakpuri 4.5mm.

Briefly, for three hours – between 12:35am and 3:35am, the IMD had issued an orange alert, forecasting moderate showers across the entire city, accompanied by strong winds.

The IMD classifies rainfall as “light” when it is up to 15.5mm, “moderate” when it is between 15.6 and 64.4mm, “heavy” when it is between 64.5mm and 115.5mm and as “very heavy” when it is over 115.5mm in a 24-hour window.

With just six days into the month, Delhi’s rain is already in ‘excess’ for October.

Safdarjung, the base station for Delhi’s weather, had received 51.8mm, prior to this spell – over three times the monthly normal of 15.1mm. Last October, Delhi recorded zero rainfall. Showers on Monday and Tuesday are expected to add to this total, pushing 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 average of 30.7mm.

In June, Delhi recorded 107.1mm of monthly rainfall, an excess of 45% over the 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, the retreat of the monsoon was declared on September 24, the earliest in Delhi since 2002, when it departed on September 20. Last year, the monsoon had withdrawn 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 temperature on Sunday stood at 34.1°C – around normal. This is forecast to dip to around 28°C on Monday, owing to overcast skies and rain. Sunday’s 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, officials said.

The rain has also had a positive impact on Delhi’s air. The 24-hour average air quality index (AQI) stood at 120 (moderate) at 8am on Monday – down from a reading of 159 (satisfactory) at 4pm on Sunday. This is forecast to improve further and dip below 100 in the second half of the day.