The sun played peekaboo on Monday as a slow but persistent breeze blew away the cloud cover that promised rain and relief from the prickly heat and humidity over the past couple of days.

The city suffered the sultriest day with the minimum relative humidity settling at 65 per cent, the highest since February 17.

Back then, however, the temperature ranged between 20.8 and 19.2 degrees Celsius and 9.9mm of rainfall made the weather as pleasant as it could get.

The sky has been generally cloudy over the past few days, but did not open up the way the weather office said it would. A blink-and-miss drizzle on Sunday evening again raised hope.

Met officials said the weather co-ordinates suggested a downpour but the clouds were not laden with enough moisture for precipitation because the trough of low pressure could not gain enough height to attract water particles.

Monday evening was a carbon copy of the previous day — the wind picked up speed at dusk accompanied by thunder and lightning, it started drizzling on cue but fizzled out even before people realised what happened.

“The rain has been playing truant for the past few days. The day was so muggy that I hoped against hope for a strong rain. I thought my prayers were answered when a few drops fell from the sky. But saw people starting to fold back their umbrellas seconds after opening them. I understood…today was no different,” said Arijit Banerjee, a Sector V techie who was in a bus at 6pm on the way to his Ultandanga home.

Since the trough of low pressure extending from north India to coastal Bangladesh has failed the city, it could now pin its hopes only on a Nor’wester originating in the Chhotanagpur plateau and fed with moisture all along the way.

“On Sunday, there was plenty of moisture in the Calcutta air but a Nor’wester that brought rain to Jamshedpur did not move towards the city. A strong breeze hit the city on Thursday without carrying enough rain-bearing clouds. That’s why the city had to be content with light rain that hardly registers,” a senior meteorologist said.

The cloud cover acted like a giant sunscreen, keeping the maximum temperature at a degree below normal. It read 34.3 degrees Celsius, one degree below normal for the first time in 14 days.

“The maximum temperature was down, no doubt. But the minimum relative humidity was very high. It was unusually uncomfortable because the moisture-laden air blocked evaporation of sweat. Humidity plays a more important role in the discomfort index than temperature,” said a scientist with the India Meteorological Department in the city.

The discomfort index recorded at 2.30pm was 62.6 degrees Celsius, almost eight notches above the comfort zone.

The Alipore Met office gave fresh hope with a forecast of rain or thundershower in the next 24 hours.

The squall warning has been withdrawn for Calcutta and all south Bengal districts, except Birbhum, Nadia and Murshidabad, with the trough weakening a bit.