Delhi gets first chill of season as intense rain brings temp, visibility down; flight ops hit

As many as 100 flights were delayed and 15 diverted from Delhi to nearby areas due to the rains, officials said.

Residents in the city witnessed intense rain and a pleasant chill on Tuesday as a prevailing western disturbance continued to make an impact, leading to a drop in temperature and even visibility during the day. As per the India Meteorological Department (IMD) forecast, no more rain is expected, with a further drop in the minimum temperature.

Visitors at the Red Fort during the rainfall on Tuesday evening. (RAJ K RAJ /HT PHOTO)

As many as 100 flights were delayed and 15 diverted from Delhi to nearby areas due to the rains, officials said. “This included eight to Jaipur, five flights to Lucknow, and two to Chandigarh,” said an airport official. A flight is classified as “delayed” if it is late by 15 minutes or more.

While light overnight showers were recorded first between 2am and 5am, a second, more intense spell was recorded during the day between 2.30pm and 5.30pm, with dark grey clouds dominating the city skyline. Delhi’s minimum can now dip by 1-2°C beginning Wednesday after fresh snowfall in the upper reaches of the Himalayas, officials said.

In the 24 hours till 8.30am on Tuesday, Safdarjung, the city’s base station, logged 12.6mm of rainfall, recording another 5.8mm in the next nine hours, data till 5.30pm showed.

Between 8.30am and 5.30pm, Palam (IGI airport) logged 41.6mm rainfall while 5.8mm was logged at Lodhi road, 37mm in north Delhi’s Ridge, 5.1mm in Ayanagar, 22.5mm in Pusa and 20mm in Mayur Vihar.

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.

“The rain was due to an active western disturbance, which exists as an induced low pressure area over north Rajasthan and adjoining Haryana. An associated upper air cyclonic circulation also extends upto 9.6km above the mean sea level, tilting northwestwards with height,” said an IMD official, adding that the impact of the western disturbance will be over by Wednesday.

The IMD also said Palam reported a visibility of around 6,000 metres at 1.30pm, dropping to 1,200 metres by 5pm due to the rain.

Following the spell on Tuesday, Safdarjung has now logged 80.5mm of rainfall so far this month – over five times the monthly normal of 15.1mm. Last year, October had zero rainfall. It was 5.4mm in October 2023, but 128.6mm in 2022. The all-time record for maximum rain in October was 238.3mm in 1954.

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.

On Tuesday, Delhi’s maximum temperature was recorded at 29.8 degrees Celsius (°C), four degrees below normal, and significantly up from Monday’s 26.5°C – which was the lowest October maximum since 2023. October 17 that year logged 26.2°C.

Delhi’s minimum on Tuesday stood at 21°C, which was a degree below normal. It may dip down to 19°C by Wednesday, while hovering around 20°C till the weekend.

Mahesh Palawat, vice president at Skymet said there is a cooling effect at night when cold westerly winds return after a snowfall. “Day-time temperature will rise, but nights will be chilly,” he said.

Typically, the minimum dips below 20°C on October 13 – as per the long-period average (LPA) data of the IMD. Last year, the minimum dipped below 20°C on October 12 (18.6°C).

The rain also had a washout effect, bringing down pollutants in the city. Delhi’s 24-hour average air quality index (AQI) stood at 73 (satisfactory) at 4am on Tuesday – down from 105 (moderate) a day earlier at the same time. Forecasts by the Centre’s Air Quality Early Warning System (EWS) for Delhi shows the AQI is likely to return to “moderate” by Wednesday.