Kolkata experienced its second wettest April day in nearly 15 years as a series of nor'westers swept through the city on Wednesday night. The India Meteorological Department (IMD) has issued an orange alert for thunderstorms on Monday, which coincides with the counting day for the Assembly elections. While the Met office anticipates a few more thundershowers in the coming days, these are expected to be of lower intensity.
Orange Alert for Monday
According to H R Biswas, head of the Regional Meteorological Centre (RMC) in Kolkata, intense thunderstorm activity is likely on Monday in Kolkata, North and South 24 Parganas, Howrah, Hooghly, East and West Burdwan, Bankura, and West Midnapore. The orange alert for North and South 24 Parganas, Howrah, and West Midnapore will commence on Sunday, with some areas expected to face lightning and gusty winds.
Heavy Rainfall on Wednesday Night
An intense thunderstorm began pounding the city on Wednesday night and continued beyond midnight. The Alipore Met office recorded 52.6 mm of rain between Wednesday and Thursday morning, with most of the precipitation occurring within the first two hours. This left several pockets of the city waterlogged. This rainfall is the second-highest single-day rain in April since 2011, trailing only the 63.7 mm recorded on April 6, 2012. In comparison, April 2025 saw only 23 mm, while 2024 and 2023 recorded 0.5 mm and 34.8 mm, respectively.
Monthly Rainfall Surplus
As of now, Kolkata has received a monthly total of 99.1 mm of rain in April, which is significantly above the normal monthly average. This makes it the third-highest April rainfall since 2011. In April 2025, the city recorded 47.9 mm. Biswas noted that April's rainfall in Kolkata is approximately 74% above the normal mark. Frequent thunderstorm spells have resulted in surplus or normal rainfall across all districts of Bengal, except Malda and Murshidabad.
Temperature Drop
The substantial 24-hour rainfall also caused a notable drop in temperatures. The maximum temperature on Thursday fell to 28.2 degrees Celsius, which is 7.4 degrees below normal and the lowest daytime temperature in over a month. On Wednesday, the maximum was 32.2 degrees Celsius. The minimum temperature also plummeted to 20.4 degrees Celsius, a whopping 5.8 degrees below normal, marking the lowest minimum in about three weeks. Due to frequent thundershowers, the highest maximum temperature recorded this month was 36.8 degrees Celsius on April 23, which remains the lowest April maximum in the past 15 years.
Biswas added that temperatures are expected to remain on the lower side over the next few days, providing some relief from the heat.
