City’s feel-like temperature below 40C, no heatwave likely in next seven days...

New Delhi: The heat index, or feel-like temperature, has stayed below 40 degrees Celsius for the past three days and is expected to remain in the same range for the next 24 hours. India Meteorological Department (IMD) started sharing the heat index from Saturday.
It's not just the air temperature that impacts people on a sultry day, high humidity levels can also make the heat feel more oppressive. "On Monday, the maximum temperature was 35 degrees Celsius, two degrees above normal, at Safdarjung, the city's base station. However, the maximum temperature was in the range of 33 and 37 degrees Celsius across Delhi, with relative humidity oscillating between 16% and 70%. Hence, the heat index was less than 40%," said a Met official.
The heat index is an indication to determine the human discomfort caused due to high temperature and humidity. It is the apparent temperature felt outside, considering the impact of humidity along with temperature.
This is the second consecutive season when IMD has started measuring the heat index for the city. Before 2024, the Met department issued heatwave forecasts based on the maximum temperature and its departure from normal. It is now alerting the public and agencies about both heat index and heatwave conditions. "Heatwave conditions are unlikely in the city over the next seven days," said a Met official.
Last year, the heat index remained below 40 degrees Celsius for the entire April. However, it surpassed 50 degrees Celsius in May as the humidity levels increased. For instance, on May 22, the maximum temperature settled at 43.4 degrees Celsius, but the heat index was higher at 55.4 degrees.
"The heat index is usually high in June due to the rise in moisture. The heat index will be issued over the next few months, but it will be discontinued when there is a drop in both mercury and humidity levels," said an official.
IMD defines a heatwave day when the maximum is 4.5 degrees and more above normal temperature and the maximum is at least 40 degrees Celsius. A heatwave is also considered if the maximum temperature touches 45 degrees Celsius or above. A severe heatwave is declared when the maximum is 6.5 degrees and more above normal.