India, April 28 -- By the time the dust storm arrived on Monday evening, Delhi had already spent the day gasping. The thermometer at Safdarjung had touched 42.3 degrees Celsius, the second-hottest day of the month, three degrees above normal, the kind of heat that sits on the city like a weight. Then, without much warning, the western sky turned brown. The first dust storm of the season had arrived in the Capital.

This correspondent was on the road near Connaught Place when the light changed first. The afternoon had been still and punishing. Then the trees along the boulevard began to shiver. A tea stall owner at a corner on Baba Kharak Singh Marg scrambled to pull a plastic sheet over his setup, tucking down the edges with practised urg...