Large parts of India have been recording higher than normal temperatures since the last week of March, with weather experts attributing it to the absence of periodic light rainfall and thundershowers, typical for this time of the year, due to the lack of active western disturbances.
The IMD said the intense heat could lead to “moderate” health concerns for the vulnerable sections such as infants, the elderly and people with chronic diseases. “Hence people should avoid heat exposure, wear lightweight and light-coloured cotton clothes and cover their heads with a hat or an umbrella,” it said.
There is an increased likelihood of symptoms of heat illness in people who are either exposed to the sun for a prolonged period or doing heavy work, an IMD advisory read.
A heatwave is declared when the maximum temperature is over 40 degrees Celsius and at least 4.5 notches above normal. A severe heatwave is declared if the departure from normal temperature is more than 6.4 notches, according to the IMD.
Based on absolute recorded temperatures, a heatwave is declared when an area logs a maximum temperature of 45 degrees Celsius. A severe heatwave is declared if the maximum temperature crosses the 47-degree Celsius mark.
Vidarbha in Maharashtra and west Rajasthan have consistently reported maximum temperatures in the range of 40 degrees Celsius to 45 degrees Celsius for the past two months.
According to an analysis by green thinktank Centre for Science and Environment, the early heatwaves that began on March 11 have impacted 15 Indian states and union territories (as of April 24).
India saw its warmest March this year since the IMD began keeping records 122 years ago, amid a 71 per cent rain deficit.
(With PTI Inputs)