The week has been unseasonably warm in Calcutta and its adjoining areas, and the weatherman has said that the spell is likely to continue for the next 48 hours.
The maximum temperature in the city was pegged at 36.8 degrees Celsius on Thursday, seven degrees above normal.
G.C. Debnath, director of the weather section at the Regional Meteorological Centre at Alipore, said a change in the wind pattern had caused the temperature to rise.
'For the past one week the wind blowing in from the dry and warm areas of the western parts of the country like Gujarat and Madhya Pradesh has steadily pushed up the temperature,' Debnath said on Thursday.
A change in the wind direction could bring some relief. 'We need the wind blowing in from the north or from the east to provide some relief,' an official said.
The weatherman added that the dry, warm air was causing discomfort.
'Normally, around this time, the maximum temperature is below 30 degrees and the minimum temperature hovers around 17 degrees, ensuring comfortable days and cool nights. But the sudden change in the wind direction has pushed up the temperature since mid-February,' said an official.
Officers admitted it was difficult to predict the next change in wind pattern.
'An easterly wind around this time sometimes brings in moisture from the sea and leads to rains. But, under the circumstances, that is a remote possibility. A few spells of rain would have provided some relief to the city,' an officer said.
The warm spell coincides with the examination season, starting with Madhyamik 2006 on Friday, causing discomfort to countless students. 'We are asking parents to take extra precautions as the unseasonal rise in temperature can cause dehydration, fever and flu,' said a paediatrician.