3 min readNew DelhiMay 29, 2025 03:11 AM IST
First published on: May 28, 2025 at 09:35 AM IST
The India Meteorological Department has sounded a yellow alert on Thursday and an orange alert for Friday, anticipating thunderstorms and lightning in Delhi.
In its daily bulletin, it stated, “A fresh Western Disturbance is likely to affect Northwest India from 29th May. Under its influence, light to moderate rainfall accompanied by thunderstorm/lightning and gusty winds reaching 40-60 gusting to 70 is likely over Delhi NCR on 29th & 30th May.”
The IMD also issued a subdivision-wise rainfall probability forecast for the first time. It indicates that the Haryana-Chandigarh-Delhi subdivision is likely to receive above-normal rainfall this monsoon —114 per cent of the long-period average (LPA).
While this means that Delhi is gearing up for a wetter-than-usual rainy season, scientists at the have said that it is still too early to forecast the onset of the southwest monsoon over the national capital, despite its early advance over southern and western India.
The southwest monsoon arrived in Kerala on May 24, much ahead of the normal June 1 onset. By May 26, it had already reached Mumbai, 16 days earlier than the usual date. The rapid progress has been attributed to a combination of favourable conditions, including low-pressure developments and moisture-laden winds from the Arabian Sea, as per IMD officials.
Delhi has been rainier than usual over the past three months. Records show that despite northwest India receiving below-normal cumulative rainfall (88.8 mm vs the normal 109.9 mm) during the pre-monsoon season (March to May), Delhi recorded an exceptionally wet period. The Safdarjung weather station logged 188.9 mm of rainfall, over 200 per cent of the normal 58.8 mm.
May alone has become the wettest on record in Delhi, with the city receiving 186.4 mm of rain, nearly seven times more than the monthly average of 25.1 mm, driven by frequent thunderstorms and intense weather activity.
Seasonal outlook
The IMD’s national forecast anticipates 106 per cent of LPA rainfall for the country this monsoon. While northwest India as a region is expected to receive normal rainfall (92–108 per cent of LPA), the monsoon core zone—mainly central India—is projected to receive above-normal rainfall. Conversely, northeast India is likely to see below-normal rainfall activity.
“There is no correlation as per past data that if Kerala has received the southwest monsoon early that other parts of India will receive it at the same pace,” Dr Mrutyunjay Mohapatra, IMD Director, said. He added that monsoon progression may slow down in the coming days, making it “too early” to project its arrival over central and northwest India. The normal onset date for Delhi is June 28.
Meanwhile, Mohapatra warned of a rise in “feel-like” temperatures across the country, including Delhi, owing to increased humidity levels contributing to a higher heat index.
Outlook for June in Delhi
-Day-time temperatures: Above normal
-Warm nights: Above normal
-Heatwave days: Below normal
-Rainfall: Above normal
-While climatological data from 1993–2016 shows that Delhi typically experiences more heatwave days in June, this year’s forecast suggests a relief from intense heat, with below-normal heatwave activity expected across northwest India. However, the IMD has also cautioned that parts of northwest India may witness below-normal rainfall in June, despite overall seasonal forecasts being favourable.
Despite northwest India receiving below-normal cumulative rainfall (88.8 mm vs the normal 109.9 mm) during the pre-monsoon season (March to May), Delhi recorded an exceptionally wet period 
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