Bright and sunny, morning and afternoon; wet and breezy evening — this was most of Tuesday in Calcutta, just like Monday.

A spell of heavy rain is in store post Tuesday midnight when a low-pressure area headed west will cross the city, a Met official said on Tuesday evening.

“The low-pressure area had formed on the Bay of Bengal on Monday. It has gained strength and is now a well-marked low-pressure area. It is travelling westwards. It is expected to cross Calcutta around Tuesday midnight and trigger heavy rain thereafter,” the official said.

Tuesday morning was hot and sunny. The maximum temperature was 34.8 degrees Celsius, two notches above normal. The sky was clear for the better part of the day.

As the system came closer, the clouds started gathering. The city saw the first spell of rain after 6pm.

“The system had formed off the Myanmar coast, quite far from the city. Around 6.30pm on Tuesday, the system was more than 100km from Calcutta,” the Met official said.

The system is likely to travel west, triggering heavy rain in Jhargram, Purulia and Bankura on Wednesday.

“The weather in Calcutta is likely to remain cloudy for the first half of Wednesday. The sky will clear later,” the Met official said.