Sunday felt hot and humid, and Monday is likely to get hotter, the Met office said.

On Tuesday, another spell of thunderstorms is expected to provide temporary relief from the sweaty conditions, according to the forecast.

The maximum temperature was 32.2 degrees Celsius on Sunday. It was still two notches below normal. But the day felt hotter because of the high humidity. The minimum relative humidity was around 55%.

The mercury is expected to rise to 33 degrees on Monday.

A Met bulletin said twin weather systems were at play. “A trough runs from Bihar to Gangetic Bengal across Jharkhand at 1.5km above mean sea level. An upper air cyclonic circulation lies over north Odisha and neighbourhood at 0.9km above mean sea level,” said the bulletin.

But neither is too strong at the moment.

“Scattered and extremely localised thunderstorms may happen in some parts of the state on Monday. But the intensity and spread of the rain and winds will increase on Tuesday,” said a Met official.

Calcutta is also likely to get thunderstorms on Tuesday.

“Thundershowers are likely across the state on Tuesday. The intensity is likely to be on the higher side in north Bengal, where heavy rainfall is expected in some areas. In south Bengal, light to moderate rainfall is likely accompanied by strong winds,” said the Met official.

The gusts are likely to be stronger in Nadia, Murshidabad, North 24-Parganas and East Burdwan.

The squall season has arrived. A thunderstorm struck Calcutta and neighbouring districts around midnight on Friday.

A strong spell of rain and winds and a brief hailstorm struck Dum Dum and neighbouring areas on Thursday evening. It was a localised thunderstorm. Most parts of Calcutta were dry.

The onset of the squall season was announced by a powerful Nor’wester that
swept the city on the night of March 16.