"Monsoon has entered Jalpaiguri and Coochbehar, besides Sikkim which will be lashed by intermittent rains in the next 24 hours," Regional meteorological centre Director G C Debnath told PTI.
The weatherman said scattered rains were forecast in south Bengal districts, as also Kolkata, in the next 24 hours as a result of locally-formed clouds which could not be called a pre-monsoon shower.
Heatwave warning was re-issued in Birbhum, Bankura, Howrah and Hooghly districts for the next 24 hours when maximum temperature would be three to four degrees above normal, Met officials said.
Heatwave conditions prevailed in Kolkata during the day with the mercury ruling at little over 40 degrees Celsius till noon. In the evening, however, a short shower brought relief to the people.
But higher percentage of discomfort level would continue to torment tomorrow in Kolkata and neighbourhood, Met officials predict.
Blistering heat and high humidity continued to sweep entire south Bengal, where several heatwave deaths have been reported in the last three days.
Severity of heatwave largely affected Asansol, Kulti in Burdwan district where mercury soared to 46 degrees Celsius yesterday.