Kolkata received 10.4mm of rain around midnight, bringing showers to parts of the city after a humid day.
The India Meteorological Department (IMD) has forecast a generally cloudy sky with light to moderate rain or thundershowers very likely through Saturday.
The maximum temperature is expected to hover around 28˚C, while the minimum may be around 21˚C, with high humidity persisting.
The current weather pattern is being driven by an upper air cyclonic circulation over Gangetic West Bengal and adjoining Bangladesh, along with a trough extending from northwest Bihar to Manipur. Strong moisture incursion from the Bay of Bengal is expected to fuel enhanced thunderstorm activity across the state over the next two days.
For south Bengal, including Kolkata, thunderstorms accompanied by lightning and gusty winds reaching up to 50 to 60 kmph are likely on March 28. Similar conditions may continue into March 29, though rainfall activity is expected to become more scattered thereafter.
Between March 29 and March 30, only isolated light rain is likely in most districts. A fresh spell of light to moderate rain and thundershowers is expected at a few places on March 31, again with the possibility of gusty winds.
Rainfall activity is likely to taper off from April 1, with only isolated showers in some districts, before dry weather sets in across south Bengal by April 2.
Residents have been advised to remain cautious during thunderstorms, particularly due to lightning and strong winds that may disrupt traffic and damage vulnerable structures.
Flights delayed due to weather conditions
The weather disrupted flight operations at Netaji Subhas Chandra Bose International Airport in the early hours of Saturday, with multiple flights diverted due to thunderstorms and poor visibility.
A flight carrying union home minister Amit Shah from New Delhi was also affected by the thunderstorm activity. The aircraft landed in Kolkata at 1.20am, about 55 minutes behind its revised arrival time of 12.25am.
A FlyDubai flight from Dubai and a Thai Airways flight from Bangkok were diverted to Dhaka, while an IndiGo flight from Hyderabad was diverted to Nagpur and an Air India Express flight from Bengaluru was diverted to Lucknow. Delays were also reported for several other arrivals and departures.