1st in 15 years, May so far cooler than April in Delhi

NEW DELHI: In a pleasant but highly unusual turn in weather, the first half of May in Delhi has been cooler than April this year - a first for the city in at least 15 years, as per data from Safdarjung.Going by normal maximum temperatures, the first half of May is nearly 3 degrees hotter on average than the month of April. Climatologically, that's a considerable difference and May is generally the hottest month of the year in the city. However, this year, the average maximum temperature in May 1-15 was 36.7 degrees Celsius, nearly three notches below the normal of 39.4 degrees C. The average maximum during April was way higher at 39 degrees C, against the month's normal of 36.5 degrees C.Four days of thunderstorms behind cooler May this year This has been the second coolest May 1-15 period since 2011. The only year when May first half was even cooler was 2023, when the average maximum temperature at Safdarjung was 36 degrees C. However, unlike this year, the relatively mild May in 2023 had followed a cool April, when the average maximum temperature was 35.3 degrees C. Except for 2025, all years since 2011 (temperature records of Safdarjung are publicly available only since that year) have followed the climatological trend of May first half being warmer than April. The lowest difference in temperatures during the two periods was seen in 2022, when the average maximum was 40.4 degrees C in April and just 0.2 degrees highest at 40.6 degrees C in May 1-15. At the other end, 2015 saw a massive 5.3-degree difference when a pleasant April (average max 34.5 degrees C) gave way to a torrid May first half (average max 39.8 degrees C)."May temperatures being lower than April is unusual although it is part of weather natural variation. The main reason for this higher rainfall in May so far in contrast to dry conditions in April," said Mrutyunjay Mohapatra, chief of IMD.There have been at least four days of thunderstorm activity in May so far with Safdarjung recording 91.4mm of rain, the highest for the first half of the month in at least 15 years. By contrast, April logged just 0.7mm in a single day (April 12). IMD had forecast higher-than-normal rain in May. It had also predicted hotter than usual temperatures, which has so been not come true.However, Mohapatra said heatwave conditions are likely to develop in northwest India from around May 23. "A vortex is likely to form in Arabian Sea around that time. Since it will coincide with the likely onset of monsoon, we expect it to intensify into a cyclone. If it moves in the northwest direction, north India will dry up and temperatures will rise," Mohapatra said. Meanwhile, the relief from peak heat conditions has translated directly to energy savings. While power demand usually rises sharply in May, this year the average demand so far in Delhi this month has been 4,670 MW, lower than the demand of 4751 in the second half of April.