Several regions across India are battling an unusually intense heatwave this week, forcing school closures, straining hospitals with heat-related illnesses, and prompting afternoon “paid holidays” for construction workers.
Let’s examine the factors behind this unprecedented heat.
How Unusual is This Heatwave?
While temperatures typically peak in May and June, this season’s heatwave has been extraordinary. Northwestern and eastern India have experienced double the usual number of heatwave days, with eastern India enduring its hottest April on record.
Record-Shattering Temperatures
A heatwave is declared when temperatures soar 4.5-6.4 degrees Celsius above normal. Parts of India have smashed records, including Delhi, potentially reaching a national high of 52.9°C (127.22°F). Even with potential sensor errors, Delhi still set an all-time high of 49.9°C. Rohtak in Haryana also recorded its highest-ever temperature at 47.5°C.
Why the Sudden Surge in Temperatures?
Scientists from India’s weather department explain that while rising temperatures in May and June are normal, they are usually moderated by periodic western disturbances. These weather systems, originating in the Mediterranean Sea, bring moisture-laden winds that counteract hot, dry air from Pakistan and Afghanistan.
This year, however, western disturbances were more frequent between March and early May, but their strength diminished in recent weeks. This allowed unchecked hot air from neighboring countries to drive temperatures upward. Experts both in India and globally attribute the intensification of such weather patterns to human-caused climate change.
Why is Delhi Particularly Affected?
Delhi, with a population of roughly 20 million, is one of India’s fastest-growing areas. Its vulnerability to heatwaves stems from its location surrounded by plains, desert, and hills. Additionally, its large population, limited vegetation, and increased construction over the past two decades have intensified the “heat island effect,” exacerbating the heat.
When Will the Heat Subside?
The India Meteorological Department forecasts a gradual decline in temperatures across northwest, central, and east India over the next three days. This relief will come from an approaching western disturbance, rainfall, and the cooling influence of southwesterly winds from the Arabian Sea.