Number Theory: What led to the historic heatwave this summer?

The heat in June, anecdotal accounts suggest, was historic and unbearable. An example of such accounts is those of heat-related deaths although with medical certification of death far from foolproof, the number of heat wave deaths may not show correct trends. Can other numbers show the scale of this crisis? This first of a two-part data series looks at how maximum temperatures recorded in the past month — starting mid-May — were unprecedented for large parts of north-western India. The second part will look at signs of how bad the summer has been in other parts of the country, such as in Bihar and Odisha, where temperatures were not as record-breaking but still led to significant reports of heat-related fatalities and illness.