The figure of 203 was arrived at after adding the average number of heatwaves that scorched states during the summer.
Data on average number of heatwave episodes in states/UTs, shared by the ministry of earth sciences in Lok Sabha on Wednesday, shows that the total number of heatwave days in the country this year was over five times more than such episodes (36) in 2021 with Punjab and Haryana reporting 12 times more number of heatwave days in 2022 compared to last year when these two states recorded only two heatwave days each.
Data shows that three states —Assam, Himachal Pradesh and Karnataka — have not reported any heatwave day at all this year. Assam and Himachal Pradesh have, in fact, not reported a single heatwave day since 2011.
Qualitatively, heatwave is a condition of air temperature which becomes fatal to the human body when exposed while quantitatively, it is defined based on the temperature thresholds over a region in terms of actual tempera ture or its departure from normal.
According to India Meteorological Department (IMD), heatwave is considered if the maximum temperature of a station reaches at least 40°Cor more for plains and at least 30° Cor more for hilly regions. On the other hand, heatwaves in coastal regions may be described when maximum temperature departure is 4.5° C or more from normal, provided actual maximum temperature is 37° C or more. Heatwaves in India are occurring mainly during March to June and in some rare cases even in July . The peak month of the heat wave over India is May.
“India experienced prolonged spells of heatwave during March and April 2022. Hence, the average maximum temperature of March 2022 had been the highest for All India (33. 1 degree C) and Northwest India (30. 7 degree C) and it had been the second highest for Central India (35. 2 degree C)as per the data during the period 1901 to 2022,” said Jitendra Singh, minister of earth sciences, in Lok Sabha.
Responding to a Parliament question, asked by Congress member Gaurav Gogoi, the minister in his written response said, “The average maximum temperature of April 2022 was the highest for Central India (38. 04 degree C) and for Northwest India (36. 32 degree C) and third highest for All India (35. 3 degree C) during the period of 1901 to 2022. ”
On the impact of increased temperatures, Singh said, “Abnormal temperature events can impose severe physiological stress on the human body as the body operates best within a fairly normal temperature range. There is a marked relationship between human mortality and thermal stress. During unusually hot episodes, deaths from different causes can rise significantly with the elderly at greater risk than others. ”