The city was lashed by the season’s second Nor’wester on Monday evening, sending the mercury sliding by nearly five degrees and holding out hope for a cool poll day.

The powerful Nor’wester, with windspeeds of 50-60km per hour, hit Calcutta between 6.12pm and 6.15pm. The shower that followed lasted over an hour. Till 8.30pm, the city recorded rainfall of 21.8mm.

“Over the next 24 hours, Calcutta and other parts of south Bengal could receive widespread rainfall, hail, thundershowers and Nor’westers,” said G.C. Debnath, the director of the Regional Meteorological Centre at Alipore.