The maximum temperatures are likely to recede from Thursday in north India, which is reeling under a severe heatwave, the India Meteorological Department said.
The temperatures north and central India have soared over 47 degrees Celsius at a few places since the past four-five days.
The maximum temperature in Churu, which had recorded 50 degrees Celsius on Tuesday, was 49.6 degrees, followed by 48.9 degrees in Ganganagar and Bikaner districts of Rajasthan.
Bathinda in Punjab recorded 47.5 degrees Celsius, while it was 47.2 degrees in Delhi.
"Under the influence of a western disturbance and an east-west trough and likely occurrence of rain/thunderstorm from May 28-30, maximum temperatures over plains of north India likely to recede from May 28 onwards with substantial reduction of heat wave conditions from May 29," the IMD said.
Western disturbance is a cyclonic circulation which originates in the Mediterranean Sea. Traversing central Asia, it brings rains to the hills and plains when it comes in contact with the Himalayas.
On the progress of the southwest monsoon, the IMD said it had further advanced into some more parts of south Bay of Bengal, most parts of Andaman Sea and Andaman and Nicobar Islands.
"Conditions are becoming favourable for further advance of southwest monsoon into some parts of Maldives-Comorin area and adjoining southeast Arabian Sea, remaining parts of Andaman Sea and some more parts of south and central Bay of Bengal during next 48 hours," it added.