Weather Report: IMD Warns of Prolonged Heat Waves Across India, Coastal Regions and Gangetic Belt to Endure Till 16th June
Weather Report: IMD Warns of Prolonged Heat Waves Across India, Coastal Regions and Gangetic Belt to Endure Till 16th June
The recorded numbers surpassed the usual yearly figures for these regions by more than double.
14th June 2024
This summer, India endured what could be its lengthiest heatwave period yet, as per IMD data. Odisha endured the most severe conditions, registering the highest count of such days (27), followed by western Rajasthan (23), Gangetic West Bengal (21 days) and Delhi, Haryana, Chandigarh and west UP (20 days each) between 1st March and 9th June.
The recorded numbers surpassed the usual yearly figures for these regions by more than double. Furthermore, the heatwave persists in many areas. Delhi, for instance, has encountered three additional heatwave days since 9th June, bringing the total to 23. The IMD stated on Thursday that “severe heatwave conditions” are expected to persist over northern India for the next 4-5 days.
Heatwaves are defined as periods of exceptionally high temperatures compared to the typical conditions expected in a particular area. Consequently, the threshold temperatures for declaring a heatwave vary depending on the historical temperature norms of each region.
According to IMD data covering 1st March to 9th June, 14 out of 36 meteorological subdivisions in India have documented more than 15 days of heatwaves. These subdivisions are dispersed throughout the country, with eastern and northern India experiencing the most severe impact. Surprisingly, even cooler high-altitude areas such as Himachal Pradesh reported 12 heatwave days, followed by Sikkim (11), Jammu & Kashmir (6) and Uttarakhand (2).
Madhavan Rajeevan, a climate scientist and former secretary of the ministry of earth sciences, noted that the IMD’s map displays a significant occurrence of heatwaves across India. He stated that this outcome was anticipated and forecasted in advance. Rajeevan explained that in the year following an El Niño event, such as in 2023, there is typically an increase in the frequency of heatwaves.
Madhavan Rajeevan attributed the prolonged heatwave spell to global warming, emphasising that it compounds natural variability. He highlighted the increasing likelihood of more frequent, longer and more intense heat waves as a consequence. Rajeevan underscored the importance of adequate preparation in light of the current extended spell, which contrasts with the typical annual average of 6-8 heatwave days experienced in central and northwest India. He also outlined the criteria for declaring a heatwave, noting that it occurs when the maximum temperature reaches at least 40 degrees Celsius in the plains and 30 degrees Celsius in hilly regions, with a deviation of 4.5 to 6.4 degrees Celsius from the normal temperature.
A severe heatwave is declared if the deviation exceeds 6.5 degrees Celsius. Additionally, if the temperature reaches 45 degrees Celsius, it is automatically considered a heatwave, and if it reaches 47 degrees Celsius, a severe heatwave is declared.
In coastal regions, a heatwave is announced if the maximum temperature reaches 37 degrees Celsius or higher, with a deviation of 4.5 degrees or more from the normal. The IMD forecasted a comparable scenario for Gangetic West Bengal, Bihar, Jharkhand, northern Chhattisgarh and Odisha until 16th June. However, regions like Himachal Pradesh, Jammu and Kashmir, Uttarakhand, northwest Madhya Pradesh and northern Rajasthan are expected to witness a decrease in intensity after 16th June.
