Delhi logs wettest May ever as more rain, thunderstorms expected: IMD

Business Standard

26-05-2025

Delhi is set to experience cloudy skies, thunderstorms, and rain for the remainder of May, which has already become the wettest on record, the India Meteorological Department (IMD) said on Monday (May 26).
In its weekly forecast, the IMD said the national capital is likely to see overcast conditions with chances of thunder, lightning, and showers.
Winds are expected to blow at speeds of 30–50 kmph, with gusts reaching up to 60 kmph. Minimum temperatures will range between 25°C and 27°C, while maximum temperatures may vary from 33°C to 37°C.
Wettest May since records began
A sudden change in the weather on Saturday (May 24) brought 81.4 mm of rain in a few hours, making this May the wettest since 1901, the IMD said.
Total rainfall so far this month has reached 186.4 mm, surpassing the previous record of 165 mm set in May 2008.
Sunday's rain, classified as "heavy" by the IMD, was also the second-highest 24-hour rainfall recorded in May in Delhi. The highest remains 119.3 mm on May 20, 2021.
Storm caused by multiple weather systems
The intense downpour was triggered by the convergence of moist southeasterly winds and dry westerlies. This was further intensified by three weather systems: a western disturbance over north Punjab and Jammu & Kashmir, and two upper-air cyclonic circulations — one over northwest Uttar Pradesh and north Haryana, and the other over west Rajasthan.
Earlier this month, on May 2, Delhi had already received 77 mm of rain, according to IMD data.
Experts say the unseasonal and heavy rainfall in May is a sign of evolving weather patterns. 'While localised systems like western disturbances have contributed, the larger trend points to a warming atmosphere that holds more moisture and disrupts established seasonal rhythms,' said Vishwas Chitale, Senior Programme Lead, Council on Energy, Environment and Water (CEEW), to PTI.
In 2024, Delhi saw heavy rainfall in late June following an extreme heatwave. Chitale added that although the monsoon arrived in Kerala earlier than usual this year, it is expected to reach Delhi around its normal schedule.
However, he cautioned: 'Such extremes — in both heat and rainfall — serve as a reminder that monsoon arrival alone no longer defines climate preparedness.'
Monsoon arrives early in Mumbai
Meanwhile, the southwest monsoon reached Mumbai on Monday, marking its earliest arrival in more than 70 years, according to the IMD. The city experienced heavy rain, flooding, and disruptions to transport and flights.
'Southwest monsoon made its onset over Mumbai on May 26. This is the earliest onset in the last 75 years,' IMD scientist Sushma Nair told PTI. Normally, the monsoon reaches Mumbai around June 11.
Nair added that the previous earliest onset was May 29 — recorded in 1956, 1962, and 1971 — making this year's onset three days earlier. The monsoon also advanced into Pune on Monday, IMD officials confirmed.
Bharat Forecast System launched
In a related development, the Ministry of Earth Sciences on Monday launched a home-grown weather prediction platform called the Bharat Forecast System.
Union Minister Jitendra Singh, speaking at the launch, said the new forecasting model will boost IMD's capability in providing precise and timely weather updates.
"The time has come to see what our contribution to our target of 2047 will be in the context of IMD... Our focus should be on how much role the IMD plays in bringing the Indian economy to the top, both in terms of preventing potential loss and increasing potential gains," Singh said.
He added that IMD's forecasting infrastructure is becoming increasingly state-of-the-art, with advancements already made in cities like Chennai and Mumbai and similar improvements planned for Delhi.