The city spent a reasonably pleasant Sunday, thanks to light spells of rain and overcast conditions.

The Met office recorded close to 25mm of rain in Alipore between Saturday night and Sunday night. Light to moderate rain is still in store for the city, according to the forecast.

The showers started late on Saturday. It was more of a persistent drizzle. On Sunday morning, just when the sun was making its presence felt, another set of clouds appeared. The sky turned dark before the rain started. The conditions were breezy for a while.

The maximum temperature dropped to 31.9 degrees Celsius, four notches below normal, on Sunday. On Saturday, it was 36.2 degrees.

“A trough runs from Punjab to East Bangladesh across east Uttar Pradesh, Jharkhand, North Gangetic West Bengal at 0.9km above mean sea level. In the presence of favourable wind patterns and moisture incursion from the Bay of Bengal, enhanced thunderstorms with gusty winds accompanied by heavy rainfall activity is likely over some districts of Bengal,” said a Met bulletin on Sunday.

An official at the Regional Meteorological Centre in Alipore told The Telegraph: “Calcutta is not likely to get a squall in the next three to four days. But light rain is likely. The conditions will turn uncomfortable when the Celsius rises and there is no rain.”

The intensity of the rain and wind is higher in north Bengal, which is closer to the east-west trough.

In south Bengal, Purulia, Bankura, East and West Burdwan, Birbhum, Murshidabad and Nadia are among the districts likely to get thunderstorms.

In Calcutta, the maximum temperature is likely to be around 34 degrees on Monday.

The southwest monsoon is not far from the northeast Bay of Bengal, said the Met official.

“Conditions are favourable for further advance of southwest monsoon over some more parts of south Arabian Sea, Maldives and Comorin area; some more parts of South Bay of Bengal; some more parts of central Bay of Bengal, and some parts of northeast Bay of Bengal during next 2-3 days,” said an IMD report.

The monsoon is expected to reach Kerala and parts of northeast India between May 22 and 28, the Met official said.

Usually, the monsoon reaches Bengal four to five days after it arrives in the Northeast, said the official.

The usual date of the arrival of the monsoon in Kerala is around June 1. The usual onset date for north Bengal is June 5 and south Bengal, June 10.