The heat in Delhi is becoming increasingly unbearable. On May 23, 2024, the temperature reached 41 degrees Celsius, but it felt like a scorching 50 degrees Celsius. In the coming days, the perceived heat may rise to an astonishing 56 degrees Celsius. Despite being just one degree above the normal temperature, the heat feels extraordinarily intense.
Recent data from the Indian Meteorological Department (IMD) shows a discrepancy between recorded temperatures and the heat people actually feel. This is backed by a recent study indicating that the temperatures tolerated by Indian citizens already exceed the set limits.
Why Does the Heat Feel More Intense?
The sensation of intense heat is not solely due to high air temperatures. Humidity plays a significant role in how hot it feels. The IMD has started measuring the heat index or “feels-like” temperature, which accounts for both temperature and relative humidity to provide a more accurate representation of summer conditions.
Former IMD director Anand Sharma explained in a conversation with Aaj Tak that the lack of rain in North India, absence of clouds, and prevailing hot western winds are contributing to the current heat wave. He emphasized that this is typical for the summer season.
“March, April, and May are generally hot months. March was mild, and April was relatively cool. The heat started around mid-May,” Sharma said. “This weather is actually beneficial for farmers as it helps control pests in their fields.”
When Will Relief Come?
Sharma indicated that relief from the heat isn’t expected immediately. “We can expect the current conditions to persist for at least four to five more days,” he noted. “South India experienced a heatwave in March and April but is now seeing relief with pre-monsoon rains. North India will also get relief soon.”
Impact of El Niño and La Niña
El Niño, characterized by warm sea winds from the Pacific Ocean, is ending. This will be followed by La Niña conditions, which are typically cooler. The presence of an anti-cyclone system near the coast increases heat, while high-pressure systems bring hot winds from above. Conversely, low-pressure systems facilitate rain by drawing winds upwards.
Record High Heat Index
Since April 1 last year, the IMD has been calculating the heat index to predict heatwaves. This season, Delhi recorded the highest heat index on May 22, 2024, at 55.4 degrees Celsius. The following day, the heat index reached 50 degrees Celsius, marking the second highest temperature felt this season.
As Delhi grapples with intense heat, understanding the dynamics of temperature, humidity, and atmospheric conditions becomes crucial for predicting and coping with heatwaves. The IMD’s efforts to measure the heat index provide valuable insights for better preparation and response to extreme weather conditions.
Edited by Dr. Brijendra Kumar Mishra, (Disaster Risk Reduction Expert)