The duration of heat waves in India increased by about 2.5 days between 1961 and 2021 due to global warming, as per a report released by the India Meteorological Department (IMD).
The IMD report said, the heat waves during is only likely to increase further. By 2060, there will be an increase of about two heat waves per season; the duration of heat waves too will rise by 12-18 days by this year. Currently, on average, the maximum duration of a heat wave is two to four days. The report said, a heat wave is said to occur when the average maximum temperature is 4.5-6.4º C above the long-term average (or above 40º C in the plains, 30º C in hilly areas, or 37º C in coastal areas).
A monograph titled “Heat and Cold Waves in India: Processes and Predictability” was released on April 26 by M. Ravichandran, Secretary, Ministry of Earth Sciences (MoES). As per the report, published by the MoES, IMD and Indian Institute of Tropical Meteorology, heat waves occur in primarily two regions in India, central and north-western India as well as coastal Andhra Pradesh.
On average, the maximum duration of a heat wave is two to four days. In some areas in central and north-western India, it is more than six days, and in coastal Andhra Pradesh, more than eight. The longest heat wave exceeded a duration of 10 days at many stations in central and northwestern India, and coastal Andhra Pradesh, the report noted.
As per the report, both the frequency and duration of heat waves are increasing over central and north-western India as well as coastal Andhra Pradesh and Odisha. Between 1961 and 2021, the duration of heat waves in India increased by about 2.5 days due to global warming. Model estimates also suggested that by 2060, there will be an increase of about two heat waves and an increase in the duration of heat waves by 12-18 days. Northwest India could experience about four heat waves per season, of a total duration of 30 days. The report also warned that heat waves could spread to southern India.
It is to mention here that at least 11 people died and more than 600 others suffered from heat-related health issues after they stood out in an open ground during the government-sponsored Maharashtra Bhushan award ceremony in Navi Mumbai on April 16.—INP
