A hot and humid Sunday morning led to multiple sharp spells of rain in and around the city as another low-pressure system brewed over the Bay of Bengal.
The official forecast for Calcutta for the next couple of days is light to moderate rain.
Around 10am on Sunday, the sky was bright and sunny, and the high moisture content meant people sweated profusely. But by 2pm, the conditions had changed drastically. The Calcutta skyline looked like it was evening. The rain started soon after.
Between 8.30am and 5.30pm, the Met office recorded around 15mm of rain in Alipore. The rain was widespread and uniform.
The showers continued late into the evening at some places. However, the intensity waned.
"An upper air cyclonic circulation lies over the north Bay of Bengal. Under its influence, a low-pressure area is likely to form over the northwest Bay of Bengal and adjoining coastal areas of Bengal and Odisha during the next 24 hours.... light to moderate rainfall is likely at most places. Isolated heavy to very heavy rainfall is expected in some districts," said a Met official.
On Monday, light to moderate rain or thundershower is expected across Bengal. Heavy to very heavy rainfall (7–20cm) is likely over West Midnapore, and heavy rain (7–11cm) is likely in Purulia, Bankura, Jhargram, East Midnapore, South 24-Parganas, and West Burdwan in south Bengal.
In north Bengal, heavy rain is likely in Darjeeling, Kalimpong, and Jalpaiguri, according to the forecast.
On Tuesday as well, light to moderate rain/thundershower is likely across Bengal. In south Bengal, heavy rain is likely in East Burdwan, West Burdwan, Nadia, Birbhum, and Murshidabad. In north Bengal, heavy rain is likely in Darjeeling, Jalpaiguri, Malda, and North Dinajpur.
Monsoon rain in lower Gangetic Bengal depends on low-pressure systems over the northern parts of the Bay of Bengal. There have been successive weather systems this year to ensure consistent rain in south Bengal.
"The monsoon trough at mean sea level now passes through Bikaner (Rajasthan), Gwalior, Banda, Sidhi (all in Madhya Pradesh), Jamshedpur (Jharkhand), and Digha (East Midnapore in Bengal), and thence southeastwards to the northeast Bay of Bengal," a Met report said.
"The monsoon currents are also active. Teaming up with the low-pressure system, it is likely to cause more rain in the coming days," said the official.