The rain that spared Calcutta during Puja lashed the city a day after.

After four days of high humidity and discomfort but very little rain, the sky opened up on Wednesday (Ekadashi). The sky was overcast since the early hours and some parts got a drizzle in the morning. The downpour started around 1pm and lasted for more than three hours.

Central Calcutta was the most drenched. New Market received over 70mm of rain in five hours, according to the civic body. Dum Dum, Dhapa and Joka received 62mm, 59mm and 55mm, respectively.

In Met parlance, heavy rain translates to 60mm or more in 24 hours.

Thursday could be wet, too, but the intensity of the showers is likely to reduce, a Met official said. The sky will start clearing from Friday, the day the Puja carnival will be held on Red Road.

For many, Wednesday was the first working day after the Puja break but the heavy rain threw life out of gear.

Several thoroughfares — including Central Avenue, College Street and Bidhan Sarani in central and north Calcutta and Justice Chandra Madhab Road in Bhowanipore and New Alipore Road — were waterlogged. The rain slowed traffic to a crawl on Central Avenue, College Street, Narkeldanga Main Road, Beleghata Main Road and several other thoroughfares.

Washed away by the rain, bamboo poles from puja barricades were floating in shin-deep water on Central Avenue, giving motorists a tough time. One such pole forced the driver of a mini-truck to brake suddenly. His helper got off the truck and removed the pole.

The rain was most intense between 1pm and 3pm. Before that, the sky was pitch dark. As it rained heavily, cars plied with their lights on. Many Durga idols, headed to the immersion ghats on trucks, were wrapped in plastic sheets.

Met officials had taken into account a trough of low pressure over Bengal while predicting a rain-soaked Puja, especially a wet Navami and Dashami. The four days saw very little rain but the weather was hot and humid. A high-pressure area over the Bay of Bengal led to a lot of moisture incursion and the city sweated profusely.

The rain the city saw on the four puja days was localised. The Met office in Alipore did not record any rain on Sashthi (Friday) and Dashami (Tuesday) and 0.7mm each on the three days in between.

On Sashthi and Saptami, a low-pressure trough extended from Punjab to Jharkhand. For the next three days, the trough extended to Odisha but lacked the strength to trigger sharp spells of rain in Calcutta.

The trough intensified early on Wednesday, extending from north Bengal to Odisha. It partnered a cyclonic circulation over south coastal Odisha and triggered a downpour in Calcutta.

“We had expected the trough to become well-marked a day or two ago. But it was not strong enough to trigger substantial rain. That is why Navami and Dashami were spared of sharp spells of rain,” said G.K. Das, director, India Meteorological Department, Calcutta.