IMD classifies a heatwave when the maximum temperature exceeds 40°C and is at least 4.5°C above normal, or when it touches 45°C regardless of departure.
Delhi recorded its first citywide heatwave of the season on Saturday, with the base station at Safdarjung logging a maximum of 42.8°C — 5.1 degrees above normal — as four of five key weather stations simultaneously satisfied the India Meteorological Department’s (IMD) dual criteria for a formal declaration.
The reading is the highest April maximum at Safdarjung in four years. In April 2022, the station had recorded 43.5°C across late April.
IMD classifies a heatwave when the maximum temperature exceeds 40°C and is at least 4.5°C above normal, or when it touches 45°C regardless of departure.
Weather forecast for Sunday
A citywide declaration for Delhi requires at least two stations to meet the criteria, including Safdarjung as the base observatory. On Saturday, four of the five stations monitored met the thresholds. The Ridge station recorded the city’s highest maximum at 44.5°C, 6.1 degrees above normal. Lodhi Road registered 42.6°C (5.6 degrees above normal) and Ayanagar 43.2°C (4.8 degrees above normal). Palam recorded 42.5°C.
IMD issued a yellow alert for Sunday, warning of heatwave conditions, with a possible shift towards thunderstorm activity from April 27 onwards.
On Saturday, IMD confirmed that heatwave conditions had prevailed across the Delhi region for three consecutive days — though the department had not communicated this formally until Friday, despite queries on Thursday. “Heat wave conditions have been realised at many places over Delhi. This is the third consecutive day of heat wave realisation over Delhi region. These conditions are likely to continue till Sunday. Under the influence of setting in of lower tropospheric level easterly winds, maximum temperatures are likely to fall leading to abatement of heat wave conditions over the region from April 28,” an IMD official said.
Minimum temperatures also remained elevated. Safdarjung recorded 25.2°C, 2.5 degrees above normal; Palam logged 26.8°C, 3.5 degrees above normal. No rainfall was recorded at any station in the 24-hour period ending 5:30 pm on Saturday, sustaining the heat build-up.
The conditions are being driven by dry northwesterly winds and strong solar heating, typical contributors to early-season heatwaves in northwest India.
Will it rain in Delhi?
April heatwaves are not unusual for the capital. Delhi recorded three heatwave days between April 7 and 9 last year. April 2022 saw 11 such days; April 2017 recorded four and April 2016 one.
Mahesh Palawat, vice chairman at Skymet Weather, said: “No relief is likely until chances of some rainfall across northwest India from April 26 to 28. There could be a slight cooling effect. This is likely because of a cyclonic circulation developing over Rajasthan, with chances of rain over Punjab, Haryana and Delhi, among other places in northwest India.”
