All of a sudden, late February feels like summer.

Much of the winter was consistently cold. The first weekend of February saw the mercury drop below 15 degrees. But even after that, a faint chill persisted. Air-conditioners were not needed, and the morning tap water was still very cold.

The situation has changed in the past few days. The maximum temperature touched 30 degrees on Wednesday after nearly three months. A couple of days later, the minimum temperature also touched 20 degrees.

On Sunday, the maximum temperature was 31.2 degrees Celsius, while the minimum was 20.4 degrees Celsius. Both were marginally higher than normal, which is computed on the basis of a 30-year average.

Why does it feel so hot?

Met officials cited two main factors: the consistently cold winter that just passed and the rising humidity.

Sunday’s maximum temperature was 31.2 degrees. It was slightly above normal. But it feels much warmer because Calcuttans had almost grown accustomed to below-normal temperatures for the better part of the past two and a half months, said Met officials.

The minimum relative humidity — a marker of the moisture content in the air during the driest part of the day — was over 40 per cent on Sunday. Till a couple of days ago, it was around 25 per cent.

“More humidity means more discomfort. Rising heat, coupled with rising humidity, causes more perspiration. That is why the conditions feel like summer,” the Met official said.

Rain forecast

The Met office has discounted the possibility of any significant change in the minimum temperature in the next seven days. But some rain is expected across the state early next week. In Calcutta, the showers are most likely on Monday (February 24), said a Met
official.

“A high-pressure zone is expected to take shape over the Bay of Bengal. It will lead to moisture incursion into Bengal. In south Bengal, East and West Midnapore, Jhargram, North and South 24-Parganas, Calcutta, Howrah and
Hooghly are likely to receive rain between Monday and Tuesday. In north Bengal, Darjeeling, Kalimpong and Jalpaiguri are likely to get light rain. The showers are unlikely to
be heavy. But they will most likely be accompanied by streaks of lightning and
thunder,” said a Met official.

If Calcutta gets some
rain, it will be the first in nearly four months. The last time the Met office recorded
some precipitation in Alipore was on November 2. If it rains, the overcast conditions
may lower the maximum temperature by a couple of
degrees.

A national Met bulletin on Sunday said a well-marked low-pressure area persisted over the southwest Bay of Bengal.

“The associated cyclonic circulation extends up to 5.8km above mean sea level. It is likely to continue to move west-northwestwards initially and then gradually recurve northeastwards over the southwest Bay of Bengal during the next 48 hours,” the bulletin said.

Met officials in Calcutta said the system was unlikely to impact Bengal.