Kolkata: The city recorded its hottest day so far this summer, with the maximum temperature rising to 39.1°C on Saturday, three and a half notches above normal. With warm northwesterly winds blowing into the region, the mercury will continue to hover around the 39°C mark, said the Met office.

The districts around Kolkata are expected to receive thunderstorms Monday and Tuesday. However, it will not be enough to bring down the mercury significantly until at least May 12.A bulletin issued by the Regional Meteorological Centre (RMC) on Saturday stated: "Mainly dry westerly to northwesterly wind is likely to prevail at lower levels over the region, and consequently, hot and humid conditions are likely over the districts of south Bengal on May 10, with heatwave conditions likely over some districts from May 10. Also, in view of the availability of moisture and heating impact, the possibility of enhanced thunderstorm activity with heavy rainfall over some districts of north Bengal and isolated thunderstorm activity over some districts of south Bengal is likely."On Friday, the city recorded a maximum of 38.6°C, the highest until then. The mercury rose further on Saturday, even as the city continued to reel under sweltering heat. "Dry and hot winds are blowing into the region. We expect the maximum temperature to hover between 37°C-40°C until Tuesday. The wind pattern could change after that, and moisture may start flowing in with southwesterly winds. If that happens, the city and its surroundings will receive thunderstorms," said HR Biswas, a weather scientist at RMC. The minimum temperature stood at 29.1°C on Saturday. North 24 Parganas and South 24 Parganas may receive thunderstorms between Sunday and Monday. "There will be some impact of the rain and a drop in mercury in Kolkata, which may not last long," said Biswas.Kolkata has not received a significant spell of rain since April 30. There were some drizzles, though, that helped to keep the mercury in check until May 6. On Saturday, the real-feel temperature — a measure of how the heat feels on the skin, calculated based on factors like temperature, wind direction, humidity, and sun rays intensity, among others — stayed at 45°C, just like it was on Friday. "It will continue to remain humid and uncomfortable. It is not unusual for the mercury to touch 40°C in Kolkata in May. Last year, it touched 43°C and kept hovering around the 40°C mark for several days, even as the city experienced a heatwave. This year, the mercury touched 39°C for the first time on Saturday," said a weather official.