Delhi summer takes further thundery twist

At least 14 flights were diverted and over 350 were delayed due to adverse weather conditions between 4.30pm and 6.10pm on the day

The month has changed, but Delhi’s appetite for unpredictable weather continued, as strong and intense thunderstorms—accompanied by widespread light to moderate rainfall—blew through the city on Sunday evening. Trees were uprooted, power supply disrupted and flight operations impacted as squally winds touched a speed of 96km/hr in some instances.

Gusty winds blow through Kartavya Path. (Sanjeev Verma/HT Photo)

At least 14 flights were diverted and over 350 were delayed due to adverse weather conditions between 4.30pm and 6.10pm on the day, according to airport officials.

The India Meteorological Department (IMD) issued a yellow alert for Monday and Tuesday, forecasting similar weather, with chances of light rain, thunderstorms and winds possibly touching 60km/hr.

“Wind speed touched 96km/hr at Palam at around 4.30pm, followed by 81 km/hr at Pragati Maidan at 5.15pm. At Safdarjung, it touched 80 km/hr, also around 5.15 pm,” IMD scientist Krishna Mishra said.

He said the storm was of moderate intensity in southwest and north Delhi, but intensified as it moved towards central and east Delhi. “Rohtak and Jind had not reported speeds of more than 40km/hr and it was 39km/hr at Najafgarh.”

On the meteorological factors, Mishra said: “We currently have a western disturbance as a cyclonic circulation over north Pakistan. There is also a cyclonic circulation over Haryana at the lower tropospheric levels. This led to moisture being fed from the Arabian Sea, which created thunderstorm spells.”

IMD data showed Safdarjung, Delhi’s base station for weather, received 15.8mm of rainfall. The station at Lodhi Road recorded 12.6mm of rain, Rajghat 17.8mm, Palam 7.4mm, and Pusa 13.5mm.

There was also a sharp drop in temperature, following Sunday’s spell. It dropped by around 14°C from 38°C at 3.30pm to 24°C at 5.30pm. Delhi’s maximum temperature was 37.9°C, which was recorded before the storm hit the capital around 4.30pm.

May saw Delhi record 10 rainy days, with at least five major storms. The first on May 2 saw Safdarjung recording 77mm of rain, a dust storm, and winds up to 80km/hr. On May 17, thunderstorm winds touched 74km/hr alongside light rain. The third major storm, on May 15, saw dust-raising winds at 40-50 km/hr, slashing visibility to 1200-1500 metres for nearly 12 hours and spiking particulate matter levels. The fourth major storm hit on May 21, unleashing winds at 79km/hr and a short but intense spell of rain measuring 12mm. The last spell was on May 25, with winds of 82km/hr and heavy rainfall of 81.4mm sweeping through the city.

Mishra said the long-period average (LPA) for thunderstorms is 5.9 in May and 6 in June, including mild, moderate and severe thunderstorms. “In May, we have already seen at least five severe thunderstorms. If we count all storms, it has been above average. The last time we had similar activity was in May 2018 when we had two to three severe thunderstorms. However, this time around, not only have we seen more storms overall, but the intensity has been higher too.”

In May 2022, a similar storm on May 31 saw wind speeds touch 100km/hr in the Capital, which uprooted over 500 trees and left at least two dead.

On Sunday, several trees and branches fell during the storm, following which Delhi Traffic Police issued advisories. A large tree fell on the Outer Ring Road, affecting traffic on the carriageway from IIT towards Munirka.

“Traffic is affected on Outer Ring road in the carriageway from IIT towards Munirka due to uprooting of a tree near DDA Flats, Munirka. Kindly plan your journey accordingly,” police said.

A tree fell near Tilak Bridge, blocking a portion of the main road. Visuals also emerged of a large tree that fell on a swing at Kaveri Apartments in Vasant Kunj.

Airport officials said the diversions were necessary due to strong wind shear. Flights are unable to land or take off when strong opposing winds are blowing. Similarly, operations are impacted during lightning and thunder.

“Due to adverse weather in Delhi, four flights were diverted. This included one to Chandigarh, one to Amritsar and two to Jaipur,” said an airport official. This number was later revised to 14.

Over 350 flights were also delayed, as per the flight tracking website FlightRadar24. The average delay time was 65 minutes, it said.

The rainfall, meanwhile, helped Delhi’s air quality return to a “moderate” level on the Central Pollution Control Board’s (CPCB’s) daily bulletin. It was 197 at 4pm on Sunday, up from 241 (“poor”) recorded a day earlier. The Centre’s Air Quality Early Warning System (EWS) for Delhi forecasted the AQI to remain “moderate” until June 4.