Scorching days are ahead, the Met office warned on Sunday.

The maximum temperature was around 35°C on Sunday, which is normal for this time of the year.

But the summer has been reasonably mild so far, and the sudden surge feels more taxing.

On Wednesday, when the city was in the middle of successive thunderstorms, the maximum temperature was 26.5° Celsius.

On Sunday, the Met office issued a warning for hot and humid weather in south Bengal.

“Mainly dry westerly to northwesterly winds are likely to prevail at lower tropospheric levels over the region, and consequently, hot and humid conditions are very likely to prevail over some districts of south Bengal from April 14 to 18,” the bulletin said.

In Calcutta, the day temperature is likely to touch 37° Celsius by the middle of this week, said a Met official.

“Rain is not entirely ruled out because this is the season of thunderstorms. But any such event will be localised, not widespread, if it happens at all,” said the official.

“Heat and humidity are the two main components for the formation of rain-bearing thunderclouds. If the conditions are conducive, thunderstorms may happen in a particular area, but they will be sporadic, not widespread like the last wet spell,” the official said.

Some western districts, such as Jhargram and East and West Midnapore, are more likely to witness thunderstorms in the middle of this week.

Dry weather is likely in the rest of the districts of south Bengal, the Met bulletin said.

In north Bengal, thundershowers are likely in Darjeeling, Jalpaiguri, Kalimpong, Cooch Behar and Alipurduar. Dry weather is likely to prevail in the remaining places.

The Met office had issued an enhanced thunderstorm alert for Bengal from April 5 to 9.

On almost every day in the said period, Calcutta received thunderstorms.

Calcutta and neighbouring North and South 24-Parganas received rain accompanied by strong gusts of wind that clocked more than 70kmph on multiple days.