The northern state of Uttar Pradesh -- one of India's most impoverished -- was the worst affected, with 13 new deaths reported Monday, taking the statewide total to 62 since mid-April, the news agency said.

Other deaths due to heatstroke were reported from northern and central states.

Over the weekend, 37 people fell victim to the scorching sun.

The real toll, however, could be far higher, with many people dying from heat-related illnesses such as dehydration, heart attacks and diarrhoea in poor regions where official statistics are not well kept, officials said.

Meteorologists said, however, that relief was in sight from the blistering summer temperatures of more than 40 degrees Celsius (104 degrees Fahrenheit), with the mercury set to drop in the coming days as the monsoon pushes north.

New Delhi recorded its hottest day of the year on Saturday at 44.9C, nearly five degrees above normal, the local weather centre said.

"Winds are coming from Rajasthan and Pakistan which are very high in temperatures -- winds blowing from hotter areas will bring in heat," S.C. Bhan, the head of the Delhi weather office, told AFP.

Bhan also said the lack of pre-monsoon rain in the region for the past 10 days was a key cause of the sizzling heat, but added that temperatures would drop back to normal by midweek.