The maximum temperature shot up to 39.6 degrees Celsius in Calcutta on Sunday, four degrees above normal, making it the hottest day of the season so far.

“Had the maximum temperature risen by another degree, we would have declared a heat wave,” said G.C. Debnath, the director of the weather section at Regional Meteorological Centre, Alipore.

Meteorologists declare a heat wave when the maximum temperature during summer shoots up five degrees above normal.

The effect was telling at Eden Gardens during the T20 IPL match, with the spectators making a beeline for the water counters even before finding their seats.

Those entering the stadium through gates 1 to 4a and 13 to 17 had to brave a cloud of dust. “The sun is baking the soil. That’s why there is so much dust,” said a college student from behind a mask.

The journey to the Eden, too, was exhausting. “On EM Bypass, the hot air hitting my face through the cab window was unbearable. I was drained,” said Arijit Banerjee, a techie.

The hot spell is expected to continue on Monday, with the Met office predicting the maximum temperature to hover around 39 degrees.

Sunday’s maximum temperature in the east — 42 degrees — was recorded in Jharsuguda, Orissa.

“The heat wave conditions in central India, Bihar, Jharkhand and Orissa had an impact on Gangetic Bengal. Besides, the wind from the sea which brings in moisture has weakened,” said an official.

The day’s comfort index was 57.6 degrees Celsius at 8.30am, the normal being 55 degrees. At one point, it went up to 62.6.

“The conditions are not favourable for a Nor’wester,” said an official.