Kolkata and several other districts of south Bengal experienced light to moderate rainfall on Friday.
The unseasonal rain in winter occurred due to western disturbances, the Met office said.
Vast swathes of south Bengal, including Kolkata, North and South 24-Parganas, Hooghly, Howrah, Jhargram, Purba Medinipur and Purba Bardhaman districts, experienced rain on Friday morning, the weather official said.
The showers will continue for the next 24 hours, and once the skies clear, there will be a slight dip in mercury levels for the next few days, the weather official added.
Kolkata received 23.2mm of rainfall from 8.30am to 11.30am, equally across the city.
Coastal town Digha and other parts of Purba Medinipur district also received rainfall.
The sky will generally be overcast with a few spells of rain in the next 24 hours, the weather official said.
Students going to attend schools and colleges, which reopened on the previous day, were inconvenienced, while the untimely rain also affected preparations for Saraswati puja on Saturday.