Parts of the city received light rain on Wednesday evening. But the showers brought little relief from the oppressive weather. Many Calcuttans said the discomfort worsened.
The twin assault of heat and humidity is likely to persist, the Met office warned.
It is the humidity that is causing more torment, Met officials said. The days feel like a pressure cooker, though the maximum temperature has not been abnormally high. On some days, it has remained just under normal. What is tilting the scale against Calcuttans is the excess humidity.
On Wednesday, the maximum temperature was 36.2°, 0.4° above normal. But the relative humidity was very high. The maximum was 95% and the minimum 64%. This means the humidity in the air stayed above 75% for most of the day, even after sundown.
Around 2.30pm on Wednesday, the temperature at Esplanade was around 36°. But the RealFeel was 45°. Standing in the open for even five minutes was a challenge.
The sky turned cloudy in the afternoon and rain started in central Calcutta around 4.30pm. Rumblings of thunder accompanied the showers. The Met office recorded around 11.5mm of rain in Alipore. It drizzled again at night, temporarily disrupting the IPL match at the Eden Gardens.
The minimum temperature was 28.5°, 2° above normal. “The high humidity is preventing a drop in temperature even after sundown. People are sweating even at home, even at night,” said a Met official in Alipore.
The maximum temperature on May 11, 2025, was 39.4°. On May 1, 2024, it was 42°, when the city was under a heat wave.
The hottest day so far this month was May 14, when the maximum temperature touched 36.6°.
While much of south Bengal is suffering, north Bengal is getting uniform and widespread rainfall.
“In view of favourable wind patterns and strong moisture incursion from Bay of Bengal, enhanced thunderstorms and associated activities very likely to continue over the districts of north Bengal and some districts of south Bengal. Also, hot and humid conditions are very likely at some places in the western districts (like Purulia, Bankura, Jhargram and West Midnapore) of south Bengal,” said a Met bulletin.
“An upper air cyclonic circulation lies over Gangetic Bengal and adjoining Bangladesh at 1.5km above mean sea level. Another upper air cyclonic circulation lies over west Bihar and neighbourhood at 0.9km above mean sea level.”
Darjeeling, Jalpaiguri, Alipurduar, Kalimpong and Cooch Behar are likely to receive heavy rain over the next three days.
Humidity is expected to remain “near normal to slightly above normal” in the coastal areas of south Bengal, including Calcutta.
The maximum relative humidity over the coastal districts is “likely to be 85-95%” and the minimum relative humidity “likely to be 45-65%” over the next seven days.